Mercurial > repos > deepakjadmin > mayatool3_test3

diff mayachemtools/lib/Graph.pm @ 0:73ae111cf86f draft
Uploaded
author: deepakjadmin
date: Wed, 20 Jan 2016 11:55:01 -0500
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mayachemtools/lib/Graph.pm	Wed Jan 20 11:55:01 2016 -0500
@@ -0,0 +1,4749 @@
+package Graph;
+#
+# $RCSfile: Graph.pm,v $
+# $Date: 2015/02/28 20:47:17 $
+# $Revision: 1.46 $
+#
+# Author: Manish Sud <msud@san.rr.com>
+#
+# Copyright (C) 2015 Manish Sud. All rights reserved.
+#
+# This file is part of MayaChemTools.
+#
+# MayaChemTools is free software; you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation; either version 3 of the License, or (at your option) any
+# later version.
+#
+# MayaChemTools is distributed in the hope that it will be useful, but without
+# any warranty; without even the implied warranty of merchantability of fitness
+# for a particular purpose.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with MayaChemTools; if not, see <http://www.gnu.org/licenses/> or
+# write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,
+# Boston, MA, 02111-1307, USA.
+#
+
+use strict;
+use Carp;
+use Exporter;
+use Storable ();
+use Scalar::Util ();
+use Graph::CyclesDetection;
+use Graph::PathsTraversal;
+use Graph::GraphMatrix;
+
+use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
+
+@ISA = qw(Exporter);
+@EXPORT = qw(IsGraph);
+@EXPORT_OK = qw();
+
+%EXPORT_TAGS = (all  => [@EXPORT, @EXPORT_OK]);
+
+# Setup class variables...
+my($ClassName);
+_InitializeClass();
+
+# Overload Perl functions...
+use overload '""' => 'StringifyGraph';
+
+# Class constructor...
+sub new {
+  my($Class, @VertexIDs) = @_;
+
+  # Initialize object...
+  my $This = {};
+  bless $This, ref($Class) || $Class;
+  $This->_InitializeGraph();
+
+  if (@VertexIDs) { $This->AddVertices(@VertexIDs); }
+
+  return $This;
+}
+
+# Initialize object data...
+sub _InitializeGraph {
+  my($This) = @_;
+
+  %{$This->{Vertices}} = ();
+
+  %{$This->{Edges}} = ();
+  %{$This->{Edges}->{From}} = ();
+  %{$This->{Edges}->{To}} = ();
+
+  %{$This->{Properties}} = ();
+  %{$This->{Properties}->{Graph}} = ();
+  %{$This->{Properties}->{Vertices}} = ();
+  %{$This->{Properties}->{Edges}} = ();
+}
+
+# Initialize class ...
+sub _InitializeClass {
+  #Class name...
+  $ClassName = __PACKAGE__;
+}
+
+# Add a vertex...
+sub AddVertex {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID ) {
+    carp "Warning: ${ClassName}->AddVertex: No vertex added: Vertex ID must be specified...";
+    return undef;
+  }
+  if (exists $This->{Vertices}->{$VertexID}) {
+    carp "Warning: ${ClassName}->AddVertex: Didn't add vertex $VertexID: Already exists in the graph...";
+    return undef;
+  }
+
+  $This->{Vertices}->{$VertexID} = $VertexID;
+
+  return $This;
+}
+
+# Add vertices to the graph and return graph...
+sub AddVertices {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->AddVertices: No vertices added: Vertices list is empty...";
+    return undef;
+  }
+
+  my($VertexID);
+  for $VertexID (@VertexIDs) {
+    $This->AddVertex($VertexID);
+  }
+
+  return $This;
+}
+
+# Delete a vertex...
+sub DeleteVertex {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID ) {
+    carp "Warning: ${ClassName}->DeleteVertex: No vertex deleted: Vertex ID must be specified...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID)) {
+    carp "Warning: ${ClassName}->DeleteVertex: Didn't delete vertex $VertexID: Vertex $VertexID doesn't exist...";
+    return undef;
+  }
+  $This->_DeleteVertex($VertexID);
+
+  return $This;
+}
+
+# Delete vertex...
+sub _DeleteVertex {
+  my($This, $VertexID) = @_;
+
+  # Delete corresponding edges; the corresponding edge properties are deleted during
+  # edges deletetion...
+  my(@VertexIDs);
+  @VertexIDs = $This->GetEdges($VertexID);
+  if (@VertexIDs) {
+    $This->DeleteEdges(@VertexIDs);
+  }
+
+  # Delete the vertex and any properties associated with vertex...
+  $This->DeleteVertexProperties($VertexID);
+  delete $This->{Vertices}->{$VertexID};
+}
+
+# Delete vertices...
+sub DeleteVertices {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->DeleteVertices: No vertices deleted: Vertices list is empty...";
+    return undef;
+  }
+  my($VertexID);
+  for $VertexID (@VertexIDs) {
+    $This->DeleteVertex($VertexID);
+  }
+
+  return $This;
+}
+
+# Get vertex data...
+sub GetVertex {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    return undef;
+  }
+
+  return (exists $This->{Vertices}->{$VertexID}) ? $This->{Vertices}->{$VertexID} : undef;
+}
+
+# Get data for all vertices or those specifed in the list. In scalar context, returned
+# the number of vertices found.
+#
+sub GetVertices {
+  my($This, @VertexIDs) = @_;
+  my($ValuesCount, @VertexValues);
+
+  @VertexValues = ();
+  if (@VertexIDs) {
+    @VertexValues = map { $This->GetVertex($_) } @VertexIDs;
+    $ValuesCount = grep { 1 } @VertexValues;
+  }
+  else {
+    @VertexValues = sort { $a <=> $b } keys %{$This->{Vertices}};
+    $ValuesCount = @VertexValues;
+  }
+
+  return wantarray ? @VertexValues : $ValuesCount;
+}
+
+# Is this vertex present?
+sub HasVertex {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    return 0;
+  }
+  return (exists $This->{Vertices}->{$VertexID}) ? 1 : 0;
+}
+
+# Are these vertices present? Return an array containing 1 or 0  for each vertex.
+# In scalar context, return number of vertices found.
+sub HasVertices {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    return undef;
+  }
+  my($VerticesCount, @VerticesStatus);
+
+  @VerticesStatus = map { $This->HasVertex($_) } @VertexIDs;
+  $VerticesCount = grep { 1 }  @VerticesStatus;
+
+  return wantarray ? @VerticesStatus : $VerticesCount;
+}
+
+# Add an edge...
+sub AddEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->AddEdge: No edge added: Both vertices must be defined...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID1)) {
+    carp "Warning: ${ClassName}->AddEdge: Didn't add edge between vertices $VertexID1 and $VertexID2: Vertex $VertexID1 doesn's exist...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID2)) {
+    carp "Warning: ${ClassName}->AddEdge: Didn't add edge between vertices $VertexID1 and $VertexID2: Vertex $VertexID2 doesn's exist...";
+    return undef;
+  }
+  if ($VertexID1 == $VertexID2) {
+    carp "Warning: ${ClassName}->AddEdge: Didn't add edge between vertices $VertexID1 and $VertexID2: Vertices must be different...";
+    return undef;
+  }
+  if ($This->HasEdge($VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->AddEdge: Didn't add edge between vertices $VertexID1 and $VertexID2: Edge already exists...";
+    return undef;
+  }
+
+  if (!exists $This->{Edges}->{From}->{$VertexID1}) {
+    %{$This->{Edges}->{From}->{$VertexID1}} = ();
+  }
+  $This->{Edges}->{From}->{$VertexID1}->{$VertexID2} = $VertexID2;
+
+  if (!exists $This->{Edges}->{To}->{$VertexID2}) {
+    %{$This->{Edges}->{To}->{$VertexID2}} = ();
+  }
+  $This->{Edges}->{To}->{$VertexID2}->{$VertexID1} = $VertexID1;
+
+  return $This;
+}
+
+# Add edges...
+sub AddEdges {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->AddEdges: No edges added: Vertices list is empty...";
+    return undef;
+  }
+  if (@VertexIDs % 2) {
+    carp "Warning: ${ClassName}->AddEdges: No edges added: Invalid vertices data: Input list must contain even number of vertex IDs...";
+    return undef;
+  }
+  my($VertexID1, $VertexID2, $Index);
+  for ($Index = 0; $Index < $#VertexIDs; $Index += 2) {
+    $VertexID1 = $VertexIDs[$Index]; $VertexID2 = $VertexIDs[$Index + 1];
+    $This->AddEdge($VertexID1, $VertexID2);
+  }
+
+  return $This;
+}
+
+# Delete an edge...
+sub DeleteEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->Delete: No edge deleted: Both vertices must be defined...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID1)) {
+    carp "Warning: ${ClassName}->DeleteEdge: Didn't delete edge between vertices $VertexID1 and $VertexID2: Vertex $VertexID1 doesn's exist...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID2)) {
+    carp "Warning: ${ClassName}->DeleteEdge: Didn't delete edge between vertices $VertexID1 and $VertexID2: Vertex $VertexID2 doesn's exist...";
+    return undef;
+  }
+  if (!$This->HasEdge($VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->DeleteEdge: Didn't delete edge between vertices $VertexID1 and $VertexID2: Edge doesn't exist...";
+    return undef;
+  }
+  $This->_DeleteEdge($VertexID1, $VertexID2);
+  $This->_DeleteEdge($VertexID2, $VertexID1);
+}
+
+# Delete edge...
+sub _DeleteEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  # Delete the edge...
+  if (exists $This->{Edges}->{From}->{$VertexID1}) {
+    if (exists $This->{Edges}->{From}->{$VertexID1}->{$VertexID2}) {
+      delete $This->{Edges}->{From}->{$VertexID1}->{$VertexID2};
+    }
+    if (! keys %{$This->{Edges}->{From}->{$VertexID1}}) {
+      delete $This->{Edges}->{From}->{$VertexID1};
+    }
+  }
+
+  if (exists $This->{Edges}->{To}->{$VertexID2}) {
+    if (exists $This->{Edges}->{To}->{$VertexID2}->{$VertexID1}) {
+      delete $This->{Edges}->{To}->{$VertexID2}->{$VertexID1};
+    }
+    if (! keys %{$This->{Edges}->{To}->{$VertexID2}}) {
+      delete $This->{Edges}->{To}->{$VertexID2};
+    }
+  }
+
+  # Delete properties associated with the edge...
+  $This->DeleteEdgeProperties($VertexID1, $VertexID2);
+}
+
+# Delete edges...
+sub DeleteEdges {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->DeleteEdges: No edges deleted: Vertices list is empty...";
+    return undef;
+  }
+  if (@VertexIDs % 2) {
+    carp "Warning: ${ClassName}->DeleteEdges: No edges deleted: Invalid vertices data: Input list must contain even number of vertex IDs...";
+    return undef;
+  }
+  my($VertexID1, $VertexID2, $Index);
+  for ($Index = 0; $Index < $#VertexIDs; $Index += 2) {
+    $VertexID1 = $VertexIDs[$Index]; $VertexID2 = $VertexIDs[$Index + 1];
+    $This->DeleteEdge($VertexID1, $VertexID2);
+  }
+
+  return $This;
+}
+
+# Does the edge defiend by a vertex pair exists? Edges defined from VertexID1 to VertecID2
+# and VertexID2 to VertexID1 are considered equivalent...
+sub HasEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($VertexID1) && defined($VertexID2))) {
+    return 0;
+  }
+
+  return ($This->_HasEdge($VertexID1, $VertexID2) || $This->_HasEdge($VertexID2, $VertexID1)) ? 1 : 0;
+}
+
+# Does edge exists?
+sub _HasEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  if (exists $This->{Edges}->{From}->{$VertexID1}) {
+    if (exists $This->{Edges}->{From}->{$VertexID1}->{$VertexID2}) {
+      return 1;
+    }
+  }
+  elsif (exists $This->{Edges}->{To}->{$VertexID2}) {
+    if (exists $This->{Edges}->{To}->{$VertexID2}->{$VertexID1}) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+# Do the edges defiend by vertex pairs exist? In scalar context, return the number
+# of edges found...
+sub HasEdges {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    return 0;
+  }
+  if (@VertexIDs % 2) {
+    return 0;
+  }
+  my($VertexID1, $VertexID2, $Index, $Status, $EdgesCount, @EdgesStatus);
+  @EdgesStatus = ();
+  $EdgesCount = 0;
+  for ($Index = 0; $Index < $#VertexIDs; $Index += 2) {
+    $VertexID1 = $VertexIDs[$Index]; $VertexID2 = $VertexIDs[$Index + 1];
+    $Status = $This->HasEdge($VertexID1, $VertexID2);
+    push @EdgesStatus, ($Status);
+    if (defined($Status) && $Status) {
+      $EdgesCount++;
+    }
+  }
+  return wantarray ? @EdgesStatus : $EdgesCount;
+}
+
+# Get edges for a vertex ID or retrieve all the edges. In scalar context,
+#  return the number of edges.
+#
+sub GetEdges {
+  my($This, $VertexID) = @_;
+  my(@VertexIDs);
+
+  @VertexIDs = ();
+  if (defined $VertexID) {
+    push @VertexIDs, ($This->_GetEdgesFrom($VertexID), $This->_GetEdgesTo($VertexID))
+  }
+  else {
+    push @VertexIDs, $This->_GetEdges();
+  }
+  return (wantarray ? @VertexIDs : @VertexIDs/2);
+}
+
+# Get edge starting from the vertex to its successor vertices...
+sub _GetEdgesFrom {
+  my($This, $VertexID1) = @_;
+  my($VertexID2) = undef;
+
+  return $This->_GetEdges($VertexID1, $VertexID2);
+}
+
+# Get edge starting from predecessors to the vertex...
+sub _GetEdgesTo {
+  my($This, $VertexID2) = @_;
+  my($VertexID1) = undef;
+
+  return $This->_GetEdges($VertexID1, $VertexID2);
+}
+
+# Get edges as pair of vertex IDs. Edges data can be retrieved in three
+# different ways:
+#
+# Both vertex IDs are defined: Returns existing edge between the vertices
+# Only first vertex ID defined: Returns all edges at the vertex
+# Only second vertex defined: Returns all edges at the vertex
+# No vertex IDs defined: Returns all edges
+#
+sub _GetEdges {
+  my($This, $VertexID1, $VertexID2) = @_;
+  my($VertexID, @VertexIDs);
+
+  @VertexIDs = ();
+
+  if (defined($VertexID1) && defined($VertexID2)) {
+    if ($This->HasEdge($VertexID1, $VertexID2)) {
+      push @VertexIDs, ($VertexID1, $VertexID2);
+    }
+  }
+  elsif (defined($VertexID1)) {
+    for $VertexID ($This->_GetNeighborsFrom($VertexID1)) {
+      push @VertexIDs, $This->_GetEdges($VertexID1, $VertexID);
+    }
+  }
+  elsif (defined($VertexID2)) {
+    for $VertexID ($This->_GetNeighborsTo($VertexID2)) {
+      push @VertexIDs, $This->_GetEdges($VertexID, $VertexID2);
+    }
+  }
+  else {
+    for $VertexID ($This->GetVertices()) {
+      push @VertexIDs, $This->_GetEdges($VertexID);
+    }
+  }
+
+  return @VertexIDs;
+}
+
+# Add edges between successive pair of vertex IDs......
+sub AddPath {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->AddPath: No path added: Vertices list is empty...";
+    return undef;
+  }
+  if (@VertexIDs == 1) {
+    carp "Warning: ${ClassName}->AddPath: No path added: Invalid vertices data: Input list must contain more than on vertex ID...";
+    return undef;
+  }
+  if (!$This->HasVertices(@VertexIDs)) {
+    carp "Warning: ${ClassName}->AddPath: No path added: Some of the vertex IDs don't exist in the graph...";
+    return undef;
+  }
+  if ($This->HasPath(@VertexIDs)) {
+    carp "Warning: ${ClassName}->AddPath: No path added: Path already exist in the graph...";
+    return undef;
+  }
+  my(@PathVertexIDs);
+  @PathVertexIDs =$This-> _SetupPathVertices(@VertexIDs);
+
+  return $This->AddEdges(@PathVertexIDs);
+}
+
+
+# Delete edges between successive pair of vertex IDs......
+sub DeletePath {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->DeletePath: No path deleted: Vertices list is empty...";
+    return undef;
+  }
+  if (@VertexIDs == 1) {
+    carp "Warning: ${ClassName}->DeletePath: No path deleted: Invalid vertices data: Input list must contain more than on vertex ID...";
+    return undef;
+  }
+  if (!$This->HasVertices(@VertexIDs)) {
+    carp "Warning: ${ClassName}->DeletePath: No path deleted: Some of the vertex IDs don't exist in the graph...";
+    return undef;
+  }
+  if (!$This->HasPath(@VertexIDs)) {
+    carp "Warning: ${ClassName}->DeletePath: No path deleted: Path doesn't exist in the graph...";
+    return undef;
+  }
+  my(@PathVertexIDs);
+  @PathVertexIDs = $This->_SetupPathVertices(@VertexIDs);
+
+  return $This->DeleteEdges(@PathVertexIDs);
+}
+
+# Does the path defiend by edges between successive pairs of vertex IDs exist?
+sub HasPath {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    return 0;
+  }
+  if (@VertexIDs == 1) {
+    return 0;
+  }
+  if (!$This->HasVertices(@VertexIDs)) {
+    return 0;
+  }
+  my($Status, @PathVertexIDs);
+  @PathVertexIDs = $This->_SetupPathVertices(@VertexIDs);
+  $Status = ($This->HasEdges(@PathVertexIDs) == (@PathVertexIDs/2)) ? 1 : 0;
+
+  return $Status;
+}
+
+# Setup vertices for the path to define edges between successive pair of vertex IDs...
+sub _SetupPathVertices {
+  my($This, @VertexIDs) = @_;
+  my($VertexID1, $VertexID2, $Index, @PathVertexIDs);
+
+  @PathVertexIDs = ();
+  for $Index (0 .. ($#VertexIDs - 1)) {
+    $VertexID1 = $VertexIDs[$Index];
+    $VertexID2 = $VertexIDs[$Index + 1];
+    push @PathVertexIDs, ($VertexID1, $VertexID2);
+  }
+
+  return @PathVertexIDs;
+}
+
+# Add edges between successive pair of vertex IDs and an additional edge from the last to
+# the first ID to complete the cycle......
+sub AddCycle {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->AddCycle: No cycle added: Vertices list is empty...";
+    return undef;
+  }
+  if (@VertexIDs == 1) {
+    carp "Warning: ${ClassName}->AddCycle: No cycle added: Invalid vertices data: Input list must contain more than on vertex ID...";
+    return undef;
+  }
+  if (!$This->HasVertices(@VertexIDs)) {
+    carp "Warning: ${ClassName}->AddCycle: No cycle added: Some of the vertex IDs don't exist in the graph...";
+    return undef;
+  }
+  my($FirstVertextID) = $VertexIDs[0];
+  push @VertexIDs, ($FirstVertextID);
+
+  if ($This->HasCycle(@VertexIDs)) {
+    carp "Warning: ${ClassName}->AddCycle: No cycle added: Cycle already exist in the graph...";
+    return undef;
+  }
+
+  return $This->AddPath(@VertexIDs);
+}
+
+# Delete edges between successive pair of vertex IDs and an additional edge from the last to
+# the first ID to complete the cycle......
+sub DeleteCycle {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    carp "Warning: ${ClassName}->DeleteCycle: No cycle deleted: Vertices list is empty...";
+    return undef;
+  }
+  if (@VertexIDs == 1) {
+    carp "Warning: ${ClassName}->DeleteCycle: No cycle deleted: Invalid vertices data: Input list must contain more than on vertex ID...";
+    return undef;
+  }
+  if (!$This->HasVertices(@VertexIDs)) {
+    carp "Warning: ${ClassName}->DeleteCycle: No cycle deleted: Some of the vertex IDs don't exist in the graph...";
+    return undef;
+  }
+  if (!$This->HasCycle(@VertexIDs)) {
+    carp "Warning: ${ClassName}->DeleteCycle: No cycle deleted: Cycle doesn't exist in the graph...";
+    return undef;
+  }
+
+  my($FirstVertextID) = $VertexIDs[0];
+  push @VertexIDs, ($FirstVertextID);
+
+  return $This->DeletePath(@VertexIDs);
+}
+
+# Does the cycle defiend by edges between successive pairs of vertex IDs along with an additional
+# edge from last to first vertex ID exist?
+sub HasCycle {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    return 0;
+  }
+  if (@VertexIDs == 1) {
+    return 0;
+  }
+  my($FirstVertextID) = $VertexIDs[0];
+  push @VertexIDs, ($FirstVertextID);
+
+  return $This->HasPath(@VertexIDs);
+}
+
+# Get neighbors...
+sub GetNeighbors {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    return undef;
+  }
+  if (! exists $This->{Vertices}->{$VertexID}) {
+    return undef;
+  }
+
+  # Get a list of unsorted vertices and sort 'em once before returning...
+  #
+  my($VerticesCount, $SortVertices, @VertexIDs);
+
+  $SortVertices = 0;
+  @VertexIDs = ();
+
+  push @VertexIDs, $This->_GetNeighborsFrom($VertexID, $SortVertices);
+  push @VertexIDs, $This->_GetNeighborsTo($VertexID, $SortVertices);
+  $VerticesCount = @VertexIDs;
+
+  return wantarray ? sort {$a <=> $b} @VertexIDs : $VerticesCount;
+}
+
+# Get neighbors added by defining edges from the vertex. For undirected graph, it has no
+# strict meaning...
+sub _GetNeighborsFrom {
+  my($This, $VertexID, $SortVertices) = @_;
+  my(@VertexIDs);
+
+  $SortVertices = defined $SortVertices ? $SortVertices : 1;
+  @VertexIDs = ();
+
+  if (exists $This->{Edges}->{From}->{$VertexID}) {
+    push @VertexIDs, map { $This->{Edges}->{From}->{$VertexID}->{$_} }  keys %{$This->{Edges}->{From}->{$VertexID}};
+  }
+  return $SortVertices ? sort {$a <=> $b} @VertexIDs : @VertexIDs;
+}
+
+# Get neighbors added by defining edges to the vertex. For undirected graphs, it has no
+# strict meaning.
+sub _GetNeighborsTo {
+  my($This, $VertexID, $SortVertices) = @_;
+  my(@VertexIDs);
+
+  $SortVertices = defined $SortVertices ? $SortVertices : 1;
+  @VertexIDs = ();
+
+  if (exists $This->{Edges}->{To}->{$VertexID}) {
+    push @VertexIDs, map { $This->{Edges}->{To}->{$VertexID}->{$_} } keys %{$This->{Edges}->{To}->{$VertexID}};
+  }
+  return $SortVertices ? sort {$a <=> $b} @VertexIDs : @VertexIDs;
+}
+
+# Get vertex degree...
+#
+sub GetDegree {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    return undef;
+  }
+  if (! exists $This->{Vertices}->{$VertexID}) {
+    return undef;
+  }
+  my($Degree);
+  $Degree = $This->_GetInDegree($VertexID) + $This->_GetOutDegree($VertexID);
+
+  return $Degree;
+}
+
+# Get in degree added by defining edges to the vertex. For undirected graphs, it has no
+# strict meaning.
+#
+sub _GetInDegree {
+  my($This, $VertexID) = @_;
+  my($Degree);
+
+  $Degree = 0;
+  if (exists $This->{Edges}->{To}->{$VertexID}) {
+    $Degree = keys %{$This->{Edges}->{To}->{$VertexID}};
+  }
+  return $Degree;
+}
+
+# Get out degree added by defining edges from the vertex. For undirected graphs, it has no
+# strict meaning.
+#
+sub _GetOutDegree {
+  my($This, $VertexID) = @_;
+  my($Degree);
+
+  $Degree = 0;
+  if (exists $This->{Edges}->{From}->{$VertexID}) {
+    $Degree = keys %{$This->{Edges}->{From}->{$VertexID}};
+  }
+  return $Degree;
+}
+
+# Get vertex with smallest degree...
+#
+sub GetVertexWithSmallestDegree {
+  my($This) = @_;
+  my($Degree, $SmallestDegree, $SmallestDegreeVertexID, $VertexID, @VertexIDs);
+
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  if (! @VertexIDs) {
+    return undef;
+  }
+  $SmallestDegree = 99999; $SmallestDegreeVertexID = undef;
+
+  for $VertexID (@VertexIDs) {
+    $Degree = $This->_GetInDegree($VertexID) + $This->_GetOutDegree($VertexID);
+    if ($Degree < $SmallestDegree) {
+      $SmallestDegree = $Degree;
+      $SmallestDegreeVertexID = $VertexID;
+    }
+  }
+  return $SmallestDegreeVertexID;
+}
+
+# Get vertex with largest degree...
+#
+sub GetVertexWithLargestDegree {
+  my($This) = @_;
+  my($Degree, $LargestDegree, $LargestDegreeVertexID, $VertexID, @VertexIDs);
+
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  if (! @VertexIDs) {
+    return undef;
+  }
+  $LargestDegree = 0; $LargestDegreeVertexID = undef;
+
+  for $VertexID (@VertexIDs) {
+    $Degree = $This->_GetInDegree($VertexID) + $This->_GetOutDegree($VertexID);
+    if ($Degree > $LargestDegree) {
+      $LargestDegree = $Degree;
+      $LargestDegreeVertexID = $VertexID;
+    }
+  }
+  return $LargestDegreeVertexID;
+}
+
+# Get maximum degree in the graph...
+#
+sub GetMaximumDegree {
+  my($This) = @_;
+  my($Degree, $MaximumDegree, $VertexID, @VertexIDs);
+
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  if (! @VertexIDs) {
+    return undef;
+  }
+  $MaximumDegree = 0;
+
+  for $VertexID (@VertexIDs) {
+    $Degree = $This->GetDegree($VertexID);
+    if ($Degree > $MaximumDegree) {
+      $MaximumDegree = $Degree;
+    }
+  }
+  return $MaximumDegree;
+}
+
+# Get minimum degree in the graph...
+#
+sub GetMininumDegree {
+  my($This) = @_;
+  my($Degree, $MininumDegree, $VertexID, @VertexIDs);
+
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  if (! @VertexIDs) {
+    return undef;
+  }
+  $MininumDegree = 99999;
+
+  for $VertexID (@VertexIDs) {
+    $Degree = $This->GetDegree($VertexID);
+    if ($Degree < $MininumDegree) {
+      $MininumDegree = $Degree;
+    }
+  }
+  return $MininumDegree;
+}
+
+# Is it a isolated vertex?
+#
+sub IsIsolatedVertex {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    return undef;
+  }
+  if (! exists $This->{Vertices}->{$VertexID}) {
+    return undef;
+  }
+  return ($This->GetDegree() == 0) ? 1 : 0;
+}
+
+# Get all isolated vertices...
+#
+sub GetIsolatedVertices {
+  my($This) = @_;
+
+  return $This->GetVerticesWithDegreeLessThan(1);
+}
+
+# Is it a leaf vertex?
+#
+sub IsLeafVertex {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    return undef;
+  }
+  if (! exists $This->{Vertices}->{$VertexID}) {
+    return undef;
+  }
+  return ($This->GetDegree() == 1) ? 1 : 0;
+}
+
+# Get all leaf vertices...
+#
+sub GetLeafVertices {
+  my($This) = @_;
+
+  return $This->GetVerticesWithDegreeLessThan(2);
+}
+
+# Get vertices  with degree less than a specified value...
+#
+sub GetVerticesWithDegreeLessThan {
+  my($This, $SpecifiedDegree) = @_;
+  my($Degree, $VertexID, @VertexIDs, @FilteredVertexIDs);
+
+  @VertexIDs = (); @FilteredVertexIDs = ();
+
+  @VertexIDs = $This->GetVertices();
+  if (! @VertexIDs) {
+    return @FilteredVertexIDs;
+  }
+
+  for $VertexID (@VertexIDs) {
+    $Degree = $This->_GetInDegree($VertexID) + $This->_GetOutDegree($VertexID);
+    if ($Degree < $SpecifiedDegree) {
+      push @FilteredVertexIDs, $VertexID;
+    }
+  }
+  return @FilteredVertexIDs;
+}
+
+# Set a property for graph...
+sub SetGraphProperty {
+  my($This, $Name, $Value) = @_;
+
+  if (!(defined($Name) && defined($Value))) {
+    carp "Warning: ${ClassName}->SetGraphProperty: Didn't set property: Both property name and value should be specified...";
+    return undef;
+  }
+  if (exists $This->{Properties}->{Graph}->{$Name}) {
+    carp "Warning: ${ClassName}->SetGraphProperty: Didn't set property $Name: Already exists in the graph...";
+    return undef;
+  }
+
+  $This->{Properties}->{Graph}->{$Name} = $Value;
+
+  return $This;
+}
+
+# Set a properties for graph...
+sub SetGraphProperties {
+  my($This, %NamesAndValues) = @_;
+
+  if (!(keys %NamesAndValues)) {
+    carp "Warning: ${ClassName}->SetGraphProperties: Didn't set properties: Names and values list is empty...";
+    return undef;
+  }
+
+  my($Name, $Value);
+  while (($Name, $Value) = each  %NamesAndValues) {
+    $This->SetGraphProperty($Name, $Value);
+  }
+
+  return $This;
+}
+
+# Get a property value for graph...
+sub GetGraphProperty {
+  my($This, $Name) = @_;
+
+  if (!$This->HasGraphProperty($Name)) {
+    return undef;
+  }
+
+  return $This->{Properties}->{Graph}->{$Name};
+}
+
+# Get all poperty name/value pairs for graph...
+sub GetGraphProperties {
+  my($This) = @_;
+
+  return %{$This->{Properties}->{Graph}};
+}
+
+# Delete a property for graph...
+sub DeleteGraphProperty {
+  my($This, $Name) = @_;
+
+  if (!defined $Name) {
+    carp "Warning: ${ClassName}->DeleteGraphProperty: Didn't delete graph property: Name must be specified...";
+    return undef;
+  }
+  if (!$This->HasGraphProperty($Name)) {
+    carp "Warning: ${ClassName}-> DeleteGraphProperty: Didn't delete graph property $Name: Property doesn't exist...";
+    return undef;
+  }
+  delete $This->{Properties}->{Graph}->{$Name};
+
+  return $This;
+}
+
+# Delete graph properites...
+sub DeleteGraphProperties {
+  my($This) = @_;
+
+  %{$This->{Properties}->{Graph}} = ();
+
+  return $This;
+}
+
+
+# Is this property associated with graph?
+sub HasGraphProperty {
+  my($This, $Name) = @_;
+
+  if (!defined $Name) {
+    return 0;
+  }
+  return (exists $This->{Properties}->{Graph}->{$Name}) ? 1 : 0;
+}
+
+# Set a property for vertex...
+sub SetVertexProperty {
+  my($This, $Name, $Value, $VertexID) = @_;
+
+  if (!(defined($Name) && defined($Value) && defined($VertexID))) {
+    carp "Warning: ${ClassName}->SetVertexProperty: Didn't set property: Property name, value and vertexID should be specified...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID)) {
+    carp "Warning: ${ClassName}->SetVertexProperty: Didn't set property $Name for vertex $VertexID: Vertex doesn't exist...";
+    return undef;
+  }
+  if ($This->HasVertexProperty($Name, $VertexID)) {
+    carp "Warning: ${ClassName}->SetVertexProperty: Didn't set property $Name for vertex $VertexID: Property already exists...";
+    return undef;
+  }
+
+  $This->_SetVertexProperty($Name, $Value, $VertexID);
+
+  return $This;
+}
+
+# Update a property for vertex...
+sub UpdateVertexProperty {
+  my($This, $Name, $Value, $VertexID) = @_;
+
+  if (!(defined($Name) && defined($Value) && defined($VertexID))) {
+    carp "Warning: ${ClassName}->UpdateVextexProperty: Didn't update property: Property name, value and vertexID should be specified...";
+    return undef;
+  }
+  if (!$This->HasVertex($VertexID)) {
+    carp "Warning: ${ClassName}->UpdateVextexProperty: Didn't update property $Name for vertex $VertexID: Vertex doesn't exist...";
+    return undef;
+  }
+  if (!$This->HasVertexProperty($Name, $VertexID)) {
+    carp "Warning: ${ClassName}->UpdateVextexProperty: Didn't update property $Name for vertex $VertexID: Property doesn't exists...";
+    return undef;
+  }
+  $This->_SetVertexProperty($Name, $Value, $VertexID);
+
+  return $This;
+}
+
+# Set a vextex property...
+sub _SetVertexProperty {
+  my($This, $Name, $Value, $VertexID) = @_;
+
+  if (!exists $This->{Properties}->{Vertices}->{$VertexID}) {
+    %{$This->{Properties}->{Vertices}->{$VertexID}} = ();
+  }
+  $This->{Properties}->{Vertices}->{$VertexID}->{$Name} = $Value;
+
+  return $This;
+}
+
+# Set a properties for vertex..
+sub SetVertexProperties {
+  my($This, $VertexID, @NamesAndValues) = @_;
+
+  if (!defined $VertexID) {
+    carp "Warning: ${ClassName}->SetVertexProperties: Didn't set property: VertexID should be specified...";
+    return undef;
+  }
+  if (!@NamesAndValues) {
+    carp "Warning: ${ClassName}->SetVertexProperties: Didn't set property: Names and values list is empty...";
+    return undef;
+  }
+  if (@NamesAndValues % 2) {
+    carp "Warning: ${ClassName}->SetVertexProperties: Didn't set property: Invalid property name and values IDs data: Input list must contain even number of values...";
+    return undef;
+  }
+
+  my($Name, $Value, $Index);
+  for ($Index = 0; $Index < $#NamesAndValues; $Index += 2) {
+    $Name = $NamesAndValues[$Index]; $Value = $NamesAndValues[$Index + 1];
+    $This->SetVertexProperty($Name, $Value, $VertexID);
+  }
+
+  return $This;
+}
+
+
+# Set a property for vertices...
+sub SetVerticesProperty {
+  my($This, $Name, @ValuesAndVertexIDs) = @_;
+
+  if (!defined $Name) {
+    carp "Warning: ${ClassName}->SetVerticesProperty: Didn't set property: Property name should be specified...";
+    return undef;
+  }
+  if (!@ValuesAndVertexIDs) {
+    carp "Warning: ${ClassName}->SetVerticesProperty: Didn't set property: Values and vertex IDs list is empty...";
+    return undef;
+  }
+  if (@ValuesAndVertexIDs % 2) {
+    carp "Warning: ${ClassName}->SetVerticesProperty: Didn't set property: Invalid property values and vertex IDs data: Input list must contain even number of values...";
+    return undef;
+  }
+
+  my($Value, $VertexID, $Index);
+  for ($Index = 0; $Index < $#ValuesAndVertexIDs; $Index += 2) {
+    $Value = $ValuesAndVertexIDs[$Index]; $VertexID = $ValuesAndVertexIDs[$Index + 1];
+    $This->SetVertexProperty($Name, $Value, $VertexID);
+  }
+
+  return $This;
+}
+
+# Get a property value for vertex...
+sub GetVertexProperty {
+  my($This, $Name, $VertexID) = @_;
+
+  if (!$This->HasVertexProperty($Name, $VertexID)) {
+    return undef;
+  }
+
+  return $This->{Properties}->{Vertices}->{$VertexID}->{$Name};
+}
+
+# Get a property values for vertices...
+sub GetVerticesProperty {
+  my($This, $Name, @VertexIDs) = @_;
+  my($ValuesCount, @Values);
+
+  if (!@VertexIDs) {
+    @VertexIDs = ();
+    @VertexIDs = $This->GetVertices();
+  }
+  @Values = ();
+  @Values = map { $This->GetVertexProperty($Name, $_ ) } @VertexIDs;
+  $ValuesCount = grep { defined($_) } @Values;
+
+  return wantarray ? @Values : $ValuesCount;
+}
+
+# Get all property name/values pairs for vertex...
+sub GetVertexProperties {
+  my($This, $VertexID) = @_;
+
+  if (!$This->HasVertex($VertexID)) {
+    return ();
+  }
+
+  if (exists $This->{Properties}->{Vertices}->{$VertexID}) {
+    return %{$This->{Properties}->{Vertices}->{$VertexID}};
+  }
+  else {
+    return ();
+  }
+}
+
+
+# Delete a property for vertex...
+sub DeleteVertexProperty {
+  my($This, $Name, $VertexID) = @_;
+
+  if (!(defined($Name) && defined($VertexID))) {
+    carp "Warning: ${ClassName}->DeleteVertexProperty: Didn't delete property: Property name and vertex ID must be defined...";
+    return undef;
+  }
+  if (!$This->HasVertexProperty($Name, $VertexID)) {
+    carp "Warning: ${ClassName}->DeleteVertexProperty: Didn't delete property $Name for vertex $VertexID: Vertex property doesn't exist...";
+    return undef;
+  }
+  $This->_DeleteVertexProperty($VertexID, $Name);
+
+  return $This;
+}
+
+# Delete vertex property or all properties...
+sub _DeleteVertexProperty {
+  my($This, $VertexID, $Name) = @_;
+
+  if (exists $This->{Properties}->{Vertices}->{$VertexID}) {
+    if (defined $Name) {
+      if (exists $This->{Properties}->{Vertices}->{$VertexID}->{$Name}) {
+	delete $This->{Properties}->{Vertices}->{$VertexID}->{$Name};
+      }
+    }
+    else {
+      %{$This->{Properties}->{Vertices}->{$VertexID}} = ();
+    }
+    if (! keys %{$This->{Properties}->{Vertices}->{$VertexID}}) {
+      delete $This->{Properties}->{Vertices}->{$VertexID};
+    }
+  }
+  return $This;
+}
+
+# Delete a property for specified vertices or all the vertices...
+sub DeleteVerticesProperty {
+  my($This, $Name, @VertexIDs) = @_;
+
+  if (!defined $Name) {
+    carp "Warning: ${ClassName}->DeleteVerticesProperty: Didn't delete property: Property name should be specified...";
+    return undef;
+  }
+  if (!@VertexIDs) {
+    @VertexIDs = ();
+    @VertexIDs = $This->GetVertices();
+  }
+  my($VertexID);
+  for $VertexID (@VertexIDs) {
+    $This->DeleteVertexProperty($Name, $VertexID);
+  }
+
+  return $This;
+}
+
+# Delete all properities for vertex...
+sub DeleteVertexProperties {
+  my($This, $VertexID) = @_;
+
+  if (!defined $VertexID) {
+    carp "Warning: ${ClassName}->DeleteVertexProperties: Didn't delete properties: Vertex ID must be defined...";
+    return undef;
+  }
+  $This->_DeleteVertexProperty($VertexID);
+
+  return $This;
+}
+
+# Is this property associated with vertex?
+sub HasVertexProperty {
+  my($This, $Name, $VertexID) = @_;
+
+  if (!(defined($Name) && defined($VertexID))) {
+    return 0;
+  }
+
+  if (exists $This->{Properties}->{Vertices}->{$VertexID}) {
+    if (exists $This->{Properties}->{Vertices}->{$VertexID}->{$Name}) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+# Set a property for edge...
+sub SetEdgeProperty {
+  my($This, $Name, $Value, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($Name) && defined($Value) && defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->SetEdgeProperty: Didn't set property: Property name, value, vertexID1 and vertexID2 should be specified...";
+    return undef;
+  }
+  if (!$This->HasEdge($VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->SetEdgeProperty: Didn't set property $Name for edge between vertices $VertexID1 and $VertexID2: Edge doesn't exist...";
+    return undef;
+  }
+  if ($This->HasEdgeProperty($Name, $VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->SetEdgeProperty: Didn't set property $Name for edge between vertices $VertexID1 and $VertexID2: Edge property already exists...";
+    return undef;
+  }
+  $This->_SetEdgeProperty($Name, $Value, $VertexID1, $VertexID2);
+  $This->_SetEdgeProperty($Name, $Value, $VertexID2, $VertexID1);
+
+  return $This;
+}
+
+# Update a property for edge...
+sub UpdateEdgeProperty {
+  my($This, $Name, $Value, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($Name) && defined($Value) && defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->UpdateEdgeProperty: Didn't update property: Property name, value, vertexID1 and vertexID2 should be specified...";
+    return undef;
+  }
+  if (!$This->HasEdge($VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->UpdateEdgeProperty: Didn't update property $Name for edge between vertices $VertexID1 and $VertexID2: Edge doesn't exist...";
+    return undef;
+  }
+  if (!$This->HasEdgeProperty($Name, $VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->UpdateEdgeProperty: Didn't update property $Name for edge between vertices $VertexID1 and $VertexID2: Edge property doesn't exists...";
+    return undef;
+  }
+  $This->_SetEdgeProperty($Name, $Value, $VertexID1, $VertexID2);
+  $This->_SetEdgeProperty($Name, $Value, $VertexID2, $VertexID1);
+
+  return $This;
+}
+# Set a property for edges...
+sub SetEdgesProperty {
+  my($This, $Name, @ValuesAndVertexIDs) = @_;
+
+  if (!defined $Name) {
+    carp "Warning: ${ClassName}->SetEdgesProperty: Didn't set property: Property name should be specified...";
+    return undef;
+  }
+  if (!@ValuesAndVertexIDs) {
+    carp "Warning: ${ClassName}->SetEdgesProperty: Didn't set property: Values and vertex IDs list is empty...";
+    return undef;
+  }
+  if (@ValuesAndVertexIDs % 3) {
+    carp "Warning: ${ClassName}->SetEdgesProperty: Didn't set property: Invalid property values and vertex IDs data: Input list must contain triplets of values...";
+    return undef;
+  }
+
+  my($Value, $VertexID1, $VertexID2, $Index);
+  for ($Index = 0; $Index < $#ValuesAndVertexIDs; $Index += 3) {
+    $Value = $ValuesAndVertexIDs[$Index];
+    $VertexID1 = $ValuesAndVertexIDs[$Index + 1]; $VertexID2 = $ValuesAndVertexIDs[$Index + 2];
+    $This->SetEdgeProperty($Name, $Value, $VertexID1, $VertexID2);
+  }
+
+  return $This;
+}
+
+# Set a properties for a edge...
+sub SetEdgeProperties {
+  my($This, $VertexID1, $VertexID2, @NamesAndValues) = @_;
+
+  if (!(defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->SetEdgeProperties: Didn't set property: Both vertexID1 and vertexID2 should be specified...";
+    return undef;
+  }
+  if (!@NamesAndValues) {
+    carp "Warning: ${ClassName}->SetEdgeProperties: Didn't set property: Property name and values ist is empty...";
+    return undef;
+  }
+  if (@NamesAndValues % 2) {
+    carp "Warning: ${ClassName}->SetEdgeProperties: Didn't set property: Invalid property name and values data: Input list must contain triplets of values...";
+    return undef;
+  }
+
+  my($Name, $Value, $Index);
+  for ($Index = 0; $Index < $#NamesAndValues; $Index += 2) {
+    $Name = $NamesAndValues[$Index];
+    $Value = $NamesAndValues[$Index + 1];
+    $This->SetEdgeProperty($Name, $Value, $VertexID1, $VertexID2);
+  }
+
+  return $This;
+}
+
+# Set edge property...
+sub _SetEdgeProperty {
+  my($This, $Name, $Value, $VertexID1, $VertexID2) = @_;
+
+  if (!exists $This->{Properties}->{Edges}->{$VertexID1}) {
+    %{$This->{Properties}->{Edges}->{$VertexID1}} = ();
+  }
+  if (!exists $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}) {
+    %{$This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}} = ();
+  }
+  $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}->{$Name} = $Value;
+
+  return $This;
+}
+
+# Get a property value for edge...
+sub GetEdgeProperty {
+  my($This, $Name, $VertexID1, $VertexID2) = @_;
+
+  if (!$This->HasEdgeProperty($Name, $VertexID1, $VertexID2)) {
+    return undef;
+  }
+  return $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}->{$Name};
+}
+
+# Get a property values for edges...
+sub GetEdgesProperty {
+  my($This, $Name, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    @VertexIDs = ();
+    @VertexIDs = $This->GetEdges();
+  }
+  if (@VertexIDs % 2) {
+    return undef;
+  }
+
+  my($VertexID1, $VertexID2, $Index, $ValuesCount, @Values);
+  @Values = ();
+  for ($Index = 0; $Index < $#VertexIDs; $Index += 2) {
+    $VertexID1 = $VertexIDs[$Index]; $VertexID2 = $VertexIDs[$Index + 1];
+    push @Values, $This->GetEdgeProperty($Name, $VertexID1, $VertexID2);
+  }
+  $ValuesCount = grep { defined($_) } @Values;
+
+  return wantarray ? @Values : $ValuesCount;
+}
+
+# Get all property name/value paries for edge...
+sub GetEdgeProperties {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($VertexID1) && defined($VertexID2))) {
+    return ();
+  }
+  if (!exists $This->{Properties}->{Edges}->{$VertexID1}) {
+    return ();
+  }
+  if (!exists $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}) {
+    return ();
+  }
+  return %{$This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}};
+}
+
+# Delete a property for edge...
+sub DeleteEdgeProperty {
+  my($This, $Name, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($Name) && defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->DeleteEdgeProperty: Didn't delete property: Property name, vertexID1 and vertexID2 should be specified...";
+    return undef;
+  }
+  if (!$This->HasEdgeProperty($Name, $VertexID1, $VertexID2)) {
+    carp "Warning: ${ClassName}->DeleteEdgeProperty: Didn't delete property $Name for edge between vertices $VertexID1 and $VertexID2: Edge property doesn't exist...";
+    return undef;
+  }
+  $This->_DeleteEdgeProperty($VertexID1, $VertexID2, $Name);
+  $This->_DeleteEdgeProperty($VertexID2, $VertexID1, $Name);
+
+  return $This;
+}
+
+# Delete a property for edges...
+sub DeleteEdgesProperty {
+  my($This, $Name, @VertexIDs) = @_;
+
+  if (!defined $Name) {
+    carp "Warning: ${ClassName}->DeleteEdgesProperty: Didn't delete property: Property name should be specified...";
+    return undef;
+  }
+  if (!@VertexIDs) {
+    @VertexIDs = ();
+    @VertexIDs = $This->GetEdges();
+  }
+  if (@VertexIDs % 2) {
+    carp "Warning: ${ClassName}->DeleteEdgesProperty: Didn't set property: Invalid property values and vertex IDs data: Input list must contain even number of values...";
+    return undef;
+  }
+  my($Index, $VertexID1, $VertexID2);
+  for ($Index = 0; $Index < $#VertexIDs; $Index += 2) {
+    $VertexID1 = $VertexIDs[$Index]; $VertexID2 = $VertexIDs[$Index + 1];
+    $This->DeleteEdgeProperty($Name, $VertexID1, $VertexID2);
+  }
+
+  return $This;
+}
+
+# Delete all properties for edge...
+sub DeleteEdgeProperties {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($VertexID1) && defined($VertexID2))) {
+    carp "Warning: ${ClassName}->DeleteEdgeProperties: Didn't delete property: VertexID1 and vertexID2 should be specified...";
+    return undef;
+  }
+  $This->_DeleteEdgeProperty($VertexID1, $VertexID2);
+  $This->_DeleteEdgeProperty($VertexID2, $VertexID1);
+
+  return $This;
+}
+
+# Delete properties for edges...
+sub DeleteEdgesProperties {
+  my($This, @VertexIDs) = @_;
+
+  if (!@VertexIDs) {
+    @VertexIDs = ();
+    @VertexIDs = $This->GetEdges();
+  }
+  if (@VertexIDs % 2) {
+    carp "Warning: ${ClassName}->DeleteEdgesProperty: Didn't set property: Invalid property values and vertex IDs data: Input list must contain even number of values...";
+    return undef;
+  }
+  my($Index, $VertexID1, $VertexID2);
+  for ($Index = 0; $Index < $#VertexIDs; $Index += 2) {
+    $VertexID1 = $VertexIDs[$Index]; $VertexID2 = $VertexIDs[$Index + 1];
+    $This->DeleteEdgeProperties($VertexID1, $VertexID2);
+  }
+  return $This;
+}
+
+
+# Delete a specific edge property or all edge properties...
+sub _DeleteEdgeProperty {
+  my($This, $VertexID1, $VertexID2, $Name) = @_;
+
+  if (exists $This->{Properties}->{Edges}->{$VertexID1}) {
+    if (exists $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}) {
+      if (defined $Name) {
+	if (exists $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}->{$Name}) {
+	  delete $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}->{$Name};
+	}
+      }
+      else {
+	%{$This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}} = ();
+      }
+      if (! keys %{$This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}}) {
+	delete $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2};
+      }
+    }
+    if (! keys %{$This->{Properties}->{Edges}->{$VertexID1}}) {
+      delete $This->{Properties}->{Edges}->{$VertexID1};
+    }
+  }
+
+  return $This;
+}
+
+# Is this property associated with edge?
+sub HasEdgeProperty {
+  my($This, $Name, $VertexID1, $VertexID2) = @_;
+
+  if (!(defined($Name) && defined($VertexID1) && defined($VertexID2))) {
+    return 0;
+  }
+  my($Status);
+
+  $Status = ($This->_HasEdgeProperty($Name, $VertexID1, $VertexID2) || $This->_HasEdgeProperty($Name, $VertexID2, $VertexID1)) ? 1 : 0;
+
+  return $Status;
+}
+
+# Does edge proprty exists?
+sub _HasEdgeProperty {
+  my($This, $Name, $VertexID1, $VertexID2) = @_;
+
+  if (exists $This->{Properties}->{Edges}->{$VertexID1}) {
+    if (exists $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}) {
+      if (exists $This->{Properties}->{Edges}->{$VertexID1}->{$VertexID2}->{$Name}) {
+	return 1;
+      }
+    }
+  }
+  return 0;
+}
+
+# Is it a graph object?
+sub IsGraph ($) {
+  my($Object) = @_;
+
+  return _IsGraph($Object);
+}
+
+# Return a string containg vertices, edges and other properties...
+sub StringifyGraph {
+  my($This) = @_;
+  my($GraphString);
+
+  $GraphString = 'Graph:' . $This->StringifyVerticesAndEdges() . '; ' . $This->StringifyProperties();
+
+  return $GraphString;
+}
+
+# Return a string containg vertices, edges and other properties...
+sub StringifyProperties {
+  my($This) = @_;
+  my($PropertiesString);
+
+  $PropertiesString = $This->StringifyGraphProperties() . '; ' . $This->StringifyVerticesProperties(). '; ' . $This->StringifyEdgesProperties();
+
+  return $PropertiesString;
+}
+
+# Return a string containg vertices and edges...
+sub StringifyVerticesAndEdges {
+  my($This) = @_;
+  my($GraphString, $Index, $VertexID, $VertexID1, $VertexID2, $Count, @EdgeVertexIDs, @VertexIDs);
+
+  # Get vertices and edges...
+  $GraphString = '';
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  $Count = 0;
+  for $VertexID (@VertexIDs) {
+    $Count++;
+    @EdgeVertexIDs = ();
+    @EdgeVertexIDs = $This->_GetEdgesFrom($VertexID);
+    if (@EdgeVertexIDs) {
+      for ($Index = 0; $Index < $#EdgeVertexIDs; $Index += 2) {
+	$VertexID1 = $EdgeVertexIDs[$Index]; $VertexID2 = $EdgeVertexIDs[$Index + 1];
+	$GraphString .= " ${VertexID1}-${VertexID2}";
+      }
+    }
+    else {
+      $GraphString .= " ${VertexID}";
+    }
+  }
+  if (!$Count) {
+    $GraphString = 'Graph: None';
+  }
+  return $GraphString;
+}
+
+# Return a string containg graph properties...
+sub StringifyGraphProperties {
+  my($This) = @_;
+  my($Name, $Value, $Count, $GraphPropertyString, %GraphProperties);
+
+  $GraphPropertyString = "GraphProperties: ";
+  %GraphProperties = ();
+  %GraphProperties = $This->GetGraphProperties();
+  if (keys %GraphProperties) {
+    for $Name (sort keys %GraphProperties) {
+      $Value = $GraphProperties{$Name};
+      if (ref($Value) =~ /^ARRAY/) {
+	if (@{$Value}) {
+	  $GraphPropertyString .= " ${Name}=(Count: " . scalar @{$Value} . "; " . join(', ', @{$Value}) .  ")";
+	}
+	else {
+	  $GraphPropertyString .= " ${Name}=None";
+	}
+      }
+      else {
+	$GraphPropertyString .= " ${Name}=${Value}";
+      }
+    }
+  }
+  else {
+    $GraphPropertyString .= " None";
+  }
+  return $GraphPropertyString;
+}
+
+# Return a string containg vertices  properties...
+sub StringifyVerticesProperties {
+  my($This) = @_;
+  my($Name, $Value, $Count, $VertexPropertyString, $VertexID, @VertexIDs, %VertexProperties);
+
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  $Count = 0;
+  $VertexPropertyString = "VertexProperties:";
+  for $VertexID (@VertexIDs) {
+    %VertexProperties = ();
+    %VertexProperties = $This->GetVertexProperties($VertexID);
+    if (keys %VertexProperties) {
+      $Count++;
+      $VertexPropertyString .= " <Vertex ${VertexID}: ";
+      for $Name (sort keys %VertexProperties) {
+	$Value = $VertexProperties{$Name};
+	if (ref($Value) =~ /^ARRAY/) {
+	  if (@{$Value}) {
+	    $VertexPropertyString .= " ${Name}=(" . join(', ', @{$Value}) .  ")";
+	  }
+	  else {
+	    $VertexPropertyString .= " ${Name}=None";
+	  }
+	}
+	else {
+	  $VertexPropertyString .= " ${Name}=${Value}";
+	}
+      }
+      $VertexPropertyString .= ">";
+    }
+  }
+  if (!$Count) {
+    $VertexPropertyString = "VertexProperties: None";
+  }
+  return $VertexPropertyString;
+}
+
+# Return a string containg edges properties...
+sub StringifyEdgesProperties {
+  my($This) = @_;
+  my($Name, $Value, $Index, $EdgePropertyString, $Count, $VertexID, $VertexID1, $VertexID2, @EdgesVertexIDs, %EdgeProperties);
+
+  @EdgesVertexIDs = ();
+  @EdgesVertexIDs = $This->GetEdges();
+  $Count = 0;
+  $EdgePropertyString = "EdgeProperties:";
+  for ($Index = 0; $Index < $#EdgesVertexIDs; $Index += 2) {
+    $VertexID1 = $EdgesVertexIDs[$Index]; $VertexID2 = $EdgesVertexIDs[$Index + 1];
+    %EdgeProperties = ();
+    %EdgeProperties = $This->GetEdgeProperties($VertexID1, $VertexID2);
+    if (keys %EdgeProperties) {
+      $Count++;
+      $EdgePropertyString .= " <Edge ${VertexID1}-${VertexID2}:";
+      for $Name (sort keys %EdgeProperties) {
+	$Value = $EdgeProperties{$Name};
+	if (ref($Value) =~ /^ARRAY/) {
+	  if (@{$Value}) {
+	    $EdgePropertyString .= " ${Name}=(" . join(', ', @{$Value}) .  ")";
+	  }
+	  else {
+	    $EdgePropertyString .= " ${Name}=None";
+	  }
+	}
+	else {
+	  $EdgePropertyString .= " ${Name}=${Value}";
+	}
+      }
+      $EdgePropertyString .= ">";
+    }
+  }
+  if (!$Count) {
+    $EdgePropertyString = "EdgeProperties: None";
+  }
+
+  return $EdgePropertyString;
+}
+
+# Is it a graph object?
+sub _IsGraph {
+  my($Object) = @_;
+
+  return (Scalar::Util::blessed($Object) && $Object->isa($ClassName)) ? 1 : 0;
+}
+
+# Copy graph and its associated data using Storable::dclone and return a new graph...
+#
+sub Copy {
+  my($This) = @_;
+  my($NewGraph);
+
+  $NewGraph = Storable::dclone($This);
+
+  return $NewGraph;
+}
+
+# Copy vertrices and edges from This graph to NewGraph specified...
+#
+sub CopyVerticesAndEdges {
+  my($This, $NewGraph) = @_;
+
+  # Copy vertices and edges...
+  my(@Vertices, @Edges);
+  @Vertices = $This->GetVertices();
+  if (@Vertices) {
+    $NewGraph->AddVertices(@Vertices);
+  }
+  @Edges = $This->GetEdges();
+  if (@Edges) {
+    $NewGraph->AddEdges(@Edges);
+  }
+
+  return $NewGraph;
+}
+
+# Copy properties of vertices from This graph to NewGraph specified...
+#
+sub CopyVerticesProperties {
+  my($This, $NewGraph) = @_;
+
+  my($VertexID, @VertexIDs, %VertexProperties);
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  for $VertexID (@VertexIDs) {
+    %VertexProperties = (); %VertexProperties = $This->GetVertexProperties($VertexID);
+    if (keys %VertexProperties) {
+      $NewGraph->SetVertexProperties($VertexID, %VertexProperties);
+    }
+  }
+  return $NewGraph;
+}
+
+# Copy properties of edges from This graph to NewGraph specified...
+#
+sub CopyEdgesProperties {
+  my($This, $NewGraph) = @_;
+
+  my($Index, $VertexID1, $VertexID2, @EdgesVertexIDs, %EdgeProperties);
+  @EdgesVertexIDs = ();
+  @EdgesVertexIDs = $This->GetEdges();
+  for ($Index = 0; $Index < $#EdgesVertexIDs; $Index += 2) {
+    $VertexID1 = $EdgesVertexIDs[$Index]; $VertexID2 = $EdgesVertexIDs[$Index + 1];
+    %EdgeProperties = (); %EdgeProperties = $This->GetEdgeProperties($VertexID1, $VertexID2);
+    if (keys %EdgeProperties) {
+      $NewGraph->SetEdgeProperties($VertexID1, $VertexID2, %EdgeProperties);
+    }
+  }
+  return $NewGraph;
+}
+
+# Detect cycles and associate 'em to graph as graph property...
+#
+# Note:
+#   . CyclesDetection class detects all cycles in the graph and filters 'em to find
+#     independent cycles.
+#   . All cycles related methods in the graph operate on active cyclic paths. By default,
+#     active cyclic paths correspond to independent cycles. This behavior can be changed
+#     using SetActiveCyclicPaths method.
+#   . For topologically complex graphs containing large number of cycles, DetectCycles method
+#     implemented in CyclesDetection can time out in which case no cycles are detected or
+#     assigned.
+#
+sub DetectCycles {
+  my($This) = @_;
+  my($CyclesDetection);
+
+  # Delete existing graph cycles...
+  $This->_DeleteCyclesAssociatedWithGraph();
+
+  # Detect cycles...
+  $CyclesDetection = new Graph::CyclesDetection($This);
+  if (!$CyclesDetection->DetectCycles()) {
+    # Cycles detection didn't finish...
+    return undef;
+  }
+
+  # Get cycles and associate 'em to graph as properties...
+  my(@AllCyclicPaths, @IndependentCyclicPaths);
+  @AllCyclicPaths = $CyclesDetection->GetAllCyclicPaths();
+  @IndependentCyclicPaths = $CyclesDetection->GetIndependentCyclicPaths();
+
+  $This->SetGraphProperty('ActiveCyclicPaths', \@IndependentCyclicPaths);
+  $This->SetGraphProperty('AllCyclicPaths', \@AllCyclicPaths);
+  $This->SetGraphProperty('IndependentCyclicPaths', \@IndependentCyclicPaths);
+
+  # Map cycles information to vertices and edges; identify fused cycles as well...
+  return $This->_ProcessDetectedCycles();
+}
+
+# Delete any cycle properties assigned to graph, vertices and edges during detect cycles operation...
+#
+sub ClearCycles {
+  my($This) = @_;
+
+  # Delete cycle properties associated with graph...
+  $This->_DeleteCyclesAssociatedWithGraph();
+  $This->_DeleteFusedCyclesAssociatedWithGraph();
+
+  # Delete cycle properties associated with vertices and edges...
+  $This->_DeleteCyclesAssociatedWithVertices();
+  $This->_DeleteCyclesAssociatedWithEdges();
+
+  return $This;
+}
+
+# Setup cyclic paths to use during all cycle related methods. Possible values:
+# Independent or All. Default is to use Independent cyclic paths.
+#
+sub SetActiveCyclicPaths {
+  my($This, $CyclicPathsType) = @_;
+
+  if (!defined $CyclicPathsType) {
+    carp "Warning: ${ClassName}->SetActiveCyclicPaths: Didn't set active cyclic path: Cyclic path must be specified...";
+    return undef;
+  }
+  if ($CyclicPathsType !~ /^(Independent|All)$/i) {
+    carp "Warning: ${ClassName}->SetActiveCyclicPaths: Didn't set active cyclic path: Specified path type, $CyclicPathsType, is not valid. Supported valeus: Independent or All...";
+    return undef;
+  }
+  if (!$This->HasGraphProperty('ActiveCyclicPaths')) {
+    carp "Warning: ${ClassName}->SetActiveCyclicPaths: Didn't set active cyclic path: Cycles haven't been detected yet...";
+    return undef;
+  }
+  $This->DeleteGraphProperty('ActiveCyclicPaths');
+
+  my($ActiveCyclicPathsRef);
+  if ($CyclicPathsType =~ /^Independent$/i) {
+    $ActiveCyclicPathsRef = $This->GetGraphProperty('IndependentCyclicPaths');
+  }
+  elsif ($CyclicPathsType =~ /^All$/i) {
+    $ActiveCyclicPathsRef = $This->GetGraphProperty('AllCyclicPaths');
+  }
+  $This->SetGraphProperty('ActiveCyclicPaths', $ActiveCyclicPathsRef);
+
+  # Map cycles information to vertices and edges; identify fused cycles as well...
+  $This->_ProcessDetectedCycles();
+
+  return $This;
+}
+
+# Assign cycles information on to vertices and edges as vertex edge properties properties;
+# identify fused cycles as well...
+#
+sub _ProcessDetectedCycles {
+  my($This) = @_;
+
+  $This->_AssociateCyclesWithVertices();
+  $This->_AssociateCyclesWithEdgesAndIdentifyFusedCycles();
+
+  return $This;
+}
+
+# Associate cycles information to vertices as vertex properties...
+#
+sub _AssociateCyclesWithVertices {
+  my($This) = @_;
+
+  # Clear up any exisiting properties...
+  $This->_DeleteCyclesAssociatedWithVertices();
+
+  # Collects CyclicPaths for each vertex...
+  my($VertexID, $ActiveCyclicPath, $ActiveCyclicPathsRef, @CyclicPathVertexIDs, %VertexIDToCylicPaths);
+
+  %VertexIDToCylicPaths = ();
+  $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths');
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    # No cycles out there...
+    return $This;
+  }
+
+  for $ActiveCyclicPath (@{$ActiveCyclicPathsRef}) {
+    @CyclicPathVertexIDs = ();
+    @CyclicPathVertexIDs = $ActiveCyclicPath->GetVertices();
+    # Take out end vertex: It's same as start vertex for cyclic path...
+    pop @CyclicPathVertexIDs;
+    for $VertexID (@CyclicPathVertexIDs) {
+      if (!exists $VertexIDToCylicPaths{$VertexID}) {
+	@{$VertexIDToCylicPaths{$VertexID}} = ();
+      }
+      push @{$VertexIDToCylicPaths{$VertexID}}, $ActiveCyclicPath;
+    }
+  }
+
+  # Associate CyclicPaths to vertices...
+  for $VertexID (keys %VertexIDToCylicPaths) {
+    $This->SetVertexProperty('ActiveCyclicPaths', \@{$VertexIDToCylicPaths{$VertexID}}, $VertexID);
+  }
+  return $This;
+}
+
+# Associate cycles information to edges as edge properties and identify fused
+# cycles...
+#
+sub _AssociateCyclesWithEdgesAndIdentifyFusedCycles {
+  my($This) = @_;
+
+  # Delete existing cycles...
+  $This->_DeleteCyclesAssociatedWithEdges();
+  $This->_DeleteFusedCyclesAssociatedWithGraph();
+
+  # Collect cyclic paths for each edge...
+  my($Index, $VertexID1, $VertexID2, $ActiveCyclicPath, $ActiveCyclicPathsRef, $EdgeID, $EdgeIDDelimiter, $CyclesWithCommonEdgesPresent, @CyclicPathEdgeVertexIDs, %EdgeIDToCylicPaths);
+
+  %EdgeIDToCylicPaths = ();
+  $EdgeIDDelimiter = "~";
+  $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths');
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    # No cycles out there...
+    return $This;
+  }
+
+  $CyclesWithCommonEdgesPresent = 0;
+  for $ActiveCyclicPath (@{$ActiveCyclicPathsRef}) {
+    @CyclicPathEdgeVertexIDs = ();
+    @CyclicPathEdgeVertexIDs = $ActiveCyclicPath->GetEdges();
+    for ($Index = 0; $Index < $#CyclicPathEdgeVertexIDs; $Index += 2) {
+      $VertexID1 = $CyclicPathEdgeVertexIDs[$Index]; $VertexID2 = $CyclicPathEdgeVertexIDs[$Index + 1];
+      $EdgeID = ($VertexID1 < $VertexID2) ? "${VertexID1}${EdgeIDDelimiter}${VertexID2}" : "${VertexID2}${EdgeIDDelimiter}${VertexID1}";
+      if (exists $EdgeIDToCylicPaths{$EdgeID}) {
+	# A common edge between two cycles indicates a potential fused cycle...
+	$CyclesWithCommonEdgesPresent = 1;
+      }
+      else {
+	@{$EdgeIDToCylicPaths{$EdgeID}} = ();
+      }
+      push @{$EdgeIDToCylicPaths{$EdgeID}}, $ActiveCyclicPath;
+    }
+  }
+
+  # Associate CyclicPaths with edges...
+  for $EdgeID (keys %EdgeIDToCylicPaths) {
+    ($VertexID1, $VertexID2) = split($EdgeIDDelimiter, $EdgeID);
+    $This->SetEdgeProperty('ActiveCyclicPaths', \@{$EdgeIDToCylicPaths{$EdgeID}}, $VertexID1, $VertexID2);
+  }
+
+  if ($CyclesWithCommonEdgesPresent) {
+    # Identify fused cycles...
+    $This->_IdentifyAndAssociateFusedCyclesWithGraph();
+  }
+
+  return $This;
+}
+
+# Identify fused cycles and associate them to graph as graph property after cycles
+# have been associated with edges...
+#
+# Note:
+#   . During aromaticity detection, fused cycles are treated as one set for counting
+#     number of available pi electrons to check against Huckel's rule.
+#   . Fused cylce sets contain cycles with at least one common edge between pair
+#     of cycles. A specific pair of cycles might not have a direct common edge, but
+#     ends up in the same set due to a common edge with another cycle.
+#   . Fused cycles are attached to graph as 'FusedActiveCyclicPaths' property with
+#     its value as a reference to list of reference where each refernece corresponds
+#     to a list of cyclic path objects in a fused set.
+#   . For graphs containing fused cycles, non-fused cycles are separeted from fused
+#     cycles and attached to the graph as 'NonFusedActiveCyclicPaths'. It's a reference
+#     to list containing cylic path objects.
+#
+sub _IdentifyAndAssociateFusedCyclesWithGraph {
+  my($This) = @_;
+
+  # Delete exisiting fused and non-fused cycles...
+  $This->_DeleteFusedCyclesAssociatedWithGraph();
+
+  my($ActiveCyclicPathsRef);
+  $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths');
+  if (!@{$ActiveCyclicPathsRef}) {
+    # No cycles out there...
+    return $This;
+  }
+
+  # Get fused cycle pairs...
+  my($FusedCyclePairsRef, $FusedCyclesRef, $InValidFusedCycleRef);
+  ($FusedCyclePairsRef, $FusedCyclesRef, $InValidFusedCycleRef) = $This->_GetFusedCyclePairs($ActiveCyclicPathsRef);
+
+  # Get fused cycle set indices...
+  my($FusedCycleSetsIndicesRef, $FusedCycleSetsCommonEdgesRef);
+  $FusedCycleSetsIndicesRef = $This->_GetFusedCycleSetsIndices($FusedCyclePairsRef, $FusedCyclesRef);
+  if (!@{$FusedCycleSetsIndicesRef}) {
+    # No fused cycles out there...
+    return $This;
+  }
+
+  # Get fused and non-fused cycles...
+  my($FusedCycleSetsRef, $NonFusedCyclesRef);
+  ($FusedCycleSetsRef, $NonFusedCyclesRef) = $This->_GetFusedAndNonFusedCycles($ActiveCyclicPathsRef, $FusedCycleSetsIndicesRef, $InValidFusedCycleRef);
+  if (!@{$FusedCycleSetsRef}) {
+    # No fused cycles out there...
+    return $This;
+  }
+
+  # Associate fused and non fused cycles to graph....
+  $This->SetGraphProperty('FusedActiveCyclicPaths', $FusedCycleSetsRef);
+  $This->SetGraphProperty('NonFusedActiveCyclicPaths', $NonFusedCyclesRef);
+
+  return $This;
+}
+
+# Collect fused cycle pairs...
+#
+sub _GetFusedCyclePairs {
+  my($This, $ActiveCyclicPathsRef) = @_;
+
+  # Setup a CyclicPathID to CyclicPathIndex map...
+  my($CyclicPathIndex, $CyclicPathID, $ActiveCyclicPath, %CyclicPathIDToIndex);
+
+  %CyclicPathIDToIndex = ();
+  for $CyclicPathIndex (0 .. $#{$ActiveCyclicPathsRef}) {
+    $ActiveCyclicPath = $ActiveCyclicPathsRef->[$CyclicPathIndex];
+    $CyclicPathID = "$ActiveCyclicPath";
+    $CyclicPathIDToIndex{$CyclicPathID} = $CyclicPathIndex;
+  }
+  # Go over cycle edges and collect fused cycle pairs...
+  my($Index, $VertexID1, $VertexID2, $EdgeCyclicPathsRef, $EdgeID, $CyclicPath1, $CyclicPath2, $CyclicPathID1, $CyclicPathID2, $FusedCyclePairID, $FusedCyclicPath1, $FusedCyclicPath2, $FusedCyclicPathID1, $FusedCyclicPathID2, $FusedCyclicPathIndex1, $FusedCyclicPathIndex2, $FusedCyclePairEdgeCount, @CyclicPathEdgeVertexIDs, %FusedCyclePairs, %CommonEdgeVisited, %CommonEdgesCount, %FusedCycles, %InValidFusedCycles);
+
+  %FusedCyclePairs = (); %CommonEdgeVisited = ();
+  %CommonEdgesCount = ();
+  %InValidFusedCycles = (); %FusedCycles = ();
+
+  for $ActiveCyclicPath (@{$ActiveCyclicPathsRef}) {
+    @CyclicPathEdgeVertexIDs = ();
+    @CyclicPathEdgeVertexIDs = $ActiveCyclicPath->GetEdges();
+    EDGE: for ($Index = 0; $Index < $#CyclicPathEdgeVertexIDs; $Index += 2) {
+      $VertexID1 = $CyclicPathEdgeVertexIDs[$Index]; $VertexID2 = $CyclicPathEdgeVertexIDs[$Index + 1];
+      $EdgeCyclicPathsRef = $This->GetEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2);
+      if (@{$EdgeCyclicPathsRef} != 2) {
+	# Not considered a fused edge...
+	next EDGE;
+      }
+      # Set up a fused cycle pair...
+      ($FusedCyclicPath1, $FusedCyclicPath2) = @{$EdgeCyclicPathsRef};
+      ($FusedCyclicPathID1, $FusedCyclicPathID2) = ("${FusedCyclicPath1}", "${FusedCyclicPath2}");
+      ($FusedCyclicPathIndex1, $FusedCyclicPathIndex2) = ($CyclicPathIDToIndex{$FusedCyclicPathID1}, $CyclicPathIDToIndex{$FusedCyclicPathID2});
+      $FusedCyclePairID = ($FusedCyclicPathIndex1 < $FusedCyclicPathIndex2) ? "${FusedCyclicPathIndex1}-${FusedCyclicPathIndex2}" : "${FusedCyclicPathIndex2}-${FusedCyclicPathIndex1}";
+      $EdgeID = ($VertexID1 < $VertexID2) ? "${VertexID1}-${VertexID2}" : "${VertexID2}-${VertexID1}";
+
+      if (exists $FusedCyclePairs{$FusedCyclePairID}) {
+	if (exists $CommonEdgeVisited{$FusedCyclePairID}{$EdgeID}) {
+	  # Edge already processed...
+	  next EDGE;
+	}
+	$CommonEdgeVisited{$FusedCyclePairID}{$EdgeID} = $EdgeID;
+
+	$CommonEdgesCount{$FusedCyclePairID} += 1;
+	push @{$FusedCyclePairs{$FusedCyclePairID}}, $EdgeID;
+      }
+      else {
+	@{$FusedCyclePairs{$FusedCyclePairID}} = ();
+	push @{$FusedCyclePairs{$FusedCyclePairID}}, $EdgeID;
+
+	%{$CommonEdgeVisited{$FusedCyclePairID}} = ();
+	$CommonEdgeVisited{$FusedCyclePairID}{$EdgeID} = $EdgeID;
+
+	$CommonEdgesCount{$FusedCyclePairID} = 1;
+      }
+    }
+  }
+  # Valid fused cyle in fused cycle pairs must have only one common egde...
+  for $FusedCyclePairID (keys %FusedCyclePairs) {
+    ($FusedCyclicPathIndex1, $FusedCyclicPathIndex2) = split /-/, $FusedCyclePairID;
+    $FusedCycles{$FusedCyclicPathIndex1} = $FusedCyclicPathIndex1;
+    $FusedCycles{$FusedCyclicPathIndex2} = $FusedCyclicPathIndex2;
+    if (@{$FusedCyclePairs{$FusedCyclePairID}} != 1) {
+      # Mark the cycles involved as invalid fused cycles...
+      $InValidFusedCycles{$FusedCyclicPathIndex1} = $FusedCyclicPathIndex1;
+      $InValidFusedCycles{$FusedCyclicPathIndex2} = $FusedCyclicPathIndex2;
+    }
+  }
+  return (\%FusedCyclePairs, \%FusedCycles, \%InValidFusedCycles);
+}
+
+# Go over fused cycles and set up a graph to collect fused cycle sets. Graph vertices
+# correspond to cylce indices; edges correspond to pair of fused cylcles; fused cycle
+# sets correspond to connected components. Addionally set up common edges for
+# fused cycle sets.
+#
+sub _GetFusedCycleSetsIndices {
+  my($This, $FusedCyclePairsRef, $FusedCyclesRef) = @_;
+  my($FusedCyclesGraph, @FusedCycleIndices, @FusedCyclePairIndices, @FusedCycleSetsIndices);
+
+  @FusedCycleIndices = (); @FusedCyclePairIndices = ();
+  @FusedCycleSetsIndices = ();
+
+  @FusedCycleIndices = sort { $a <=> $b } keys %{$FusedCyclesRef};
+  @FusedCyclePairIndices = map { split /-/, $_; } keys %{$FusedCyclePairsRef};
+  if (!@FusedCycleIndices) {
+    # No fused cycles out there...
+    return \@FusedCycleSetsIndices;
+  }
+  $FusedCyclesGraph = new Graph(@FusedCycleIndices);
+  $FusedCyclesGraph->AddEdges(@FusedCyclePairIndices);
+
+  @FusedCycleSetsIndices = $FusedCyclesGraph->GetConnectedComponentsVertices();
+
+  return \@FusedCycleSetsIndices;
+}
+
+# Go over indices of fused cycle sets and map cyclic path indices to cyclic path objects.
+# For fused sets containing a cycle with more than one common edge, the whole set is treated
+# as non-fused set...
+#
+sub _GetFusedAndNonFusedCycles {
+  my($This, $ActiveCyclicPathsRef, $FusedCycleSetsIndicesRef, $InValidFusedCycleRef) = @_;
+  my($CycleSetIndicesRef, $CyclicPathIndex, $ValidFusedCycleSet, @FusedCycleSets, @UnsortedNonFusedCycles, @NonFusedCycles, %CycleIndexVisited);
+
+  @FusedCycleSets = (); @NonFusedCycles = (); @UnsortedNonFusedCycles = ();
+  %CycleIndexVisited = ();
+  for $CycleSetIndicesRef (@{$FusedCycleSetsIndicesRef}) {
+    # Is it a valid fused cycle set? Fused cycle set containing any cycle with more than one common
+    # edge is considered invalid and all its cycles are treated as non-fused cycles.
+    $ValidFusedCycleSet = 1;
+    for $CyclicPathIndex (@{$CycleSetIndicesRef}) {
+      $CycleIndexVisited{$CyclicPathIndex} = $CyclicPathIndex;
+      if (exists $InValidFusedCycleRef->{$CyclicPathIndex}) {
+	$ValidFusedCycleSet = 0;
+      }
+    }
+    if ($ValidFusedCycleSet) {
+      my(@FusedCycleSet);
+      @FusedCycleSet = ();
+      push @FusedCycleSet, sort { $a->GetLength() <=> $b->GetLength() } map { $ActiveCyclicPathsRef->[$_] } @{$CycleSetIndicesRef};
+      push @FusedCycleSets, \@FusedCycleSet;
+    }
+    else {
+      push @UnsortedNonFusedCycles, map { $ActiveCyclicPathsRef->[$_] } @{$CycleSetIndicesRef};
+    }
+  }
+
+  # Add any leftover cycles to non-fused cycles list...
+  CYCLICPATH: for $CyclicPathIndex (0 .. $#{$ActiveCyclicPathsRef}) {
+    if (exists $CycleIndexVisited{$CyclicPathIndex}) {
+      next CYCLICPATH;
+    }
+    push @UnsortedNonFusedCycles, $ActiveCyclicPathsRef->[$CyclicPathIndex];
+  }
+  @NonFusedCycles = sort { $a->GetLength() <=> $b->GetLength() } @UnsortedNonFusedCycles;
+
+  return (\@FusedCycleSets, \@NonFusedCycles);
+}
+
+# Delete cycles associated with graph...
+#
+sub _DeleteCyclesAssociatedWithGraph {
+  my($This) = @_;
+
+  if ($This->HasGraphProperty('ActiveCyclicPaths')) {
+    $This->DeleteGraphProperty('ActiveCyclicPaths');
+    $This->DeleteGraphProperty('AllCyclicPaths');
+    $This->DeleteGraphProperty('IndependentCyclicPaths');
+  }
+  return $This;
+}
+
+# Delete cycles associated with vertices...
+#
+sub _DeleteCyclesAssociatedWithVertices {
+  my($This) = @_;
+  my($VertexID, @VertexIDs);
+
+  @VertexIDs = ();
+  @VertexIDs = $This->GetVertices();
+  for $VertexID (@VertexIDs) {
+    if ($This->HasVertexProperty('ActiveCyclicPaths', $VertexID)) {
+      $This->DeleteVertexProperty('ActiveCyclicPaths', $VertexID);
+    }
+  }
+  return $This;
+}
+
+# Delete cycles associated with edges...
+#
+sub _DeleteCyclesAssociatedWithEdges {
+  my($This) = @_;
+  my($Index, $VertexID1, $VertexID2, @EdgeVertexIDs);
+
+  @EdgeVertexIDs = ();
+  @EdgeVertexIDs = $This->GetEdges();
+  for ($Index = 0; $Index < $#EdgeVertexIDs; $Index += 2) {
+    $VertexID1 = $EdgeVertexIDs[$Index]; $VertexID2 = $EdgeVertexIDs[$Index + 1];
+    if ($This->HasEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2)) {
+      $This->DeleteEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2);
+    }
+  }
+  return $This;
+}
+
+# Delete fused cycles associated with edges...
+#
+sub _DeleteFusedCyclesAssociatedWithGraph {
+  my($This) = @_;
+
+  # Delete exisiting cycles...
+  if ($This->HasGraphProperty('FusedActiveCyclicPaths')) {
+    $This->DeleteGraphProperty('FusedActiveCyclicPaths');
+    $This->DeleteGraphProperty('NonFusedActiveCyclicPaths');
+  }
+  return $This;
+}
+
+# Does graph contains any cycles?
+#
+sub IsAcyclic {
+  my($This) = @_;
+
+  return $This->GetNumOfCycles() ? 0 : 1;
+}
+
+# Does graph contains cycles?
+#
+sub IsCyclic {
+  my($This) = @_;
+
+  return $This->GetNumOfCycles() ? 1 : 0;
+}
+
+# Does graph contains only any cycle?
+#
+sub IsUnicyclic {
+  my($This) = @_;
+
+  return ($This->GetNumOfCycles() == 1) ? 1 : 0;
+}
+
+# Get size of smallest cycle in graph...
+#
+sub GetGirth {
+  my($This) = @_;
+
+  return $This->GetSizeOfSmallestCycle();
+}
+
+# Get size of smallest cycle in graph...
+#
+sub GetSizeOfSmallestCycle {
+  my($This) = @_;
+
+  return $This->_GetCycleSize('GraphCycle', 'SmallestCycle');
+}
+
+# Get size of largest cycle in graph...
+#
+sub GetCircumference {
+  my($This) = @_;
+
+  return $This->GetSizeOfLargestCycle();
+}
+
+# Get size of largest cycle in graph...
+#
+sub GetSizeOfLargestCycle {
+  my($This) = @_;
+
+  return $This->_GetCycleSize('GraphCycle', 'LargestCycle');
+}
+
+# Get number of cycles in graph...
+#
+sub GetNumOfCycles {
+  my($This) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('GraphCycle', 'AllSizes');
+}
+
+# Get number of cycles with odd size in graph...
+#
+sub GetNumOfCyclesWithOddSize {
+  my($This) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('GraphCycle', 'OddSize');
+}
+
+# Get number of cycles with even size in graph...
+#
+sub GetNumOfCyclesWithEvenSize {
+  my($This) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('GraphCycle', 'EvenSize');
+}
+
+# Get number of cycles with specific size in graph...
+#
+sub GetNumOfCyclesWithSize {
+  my($This, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('GraphCycle', 'SpecifiedSize', $CycleSize);
+}
+
+# Get number of cycles with size less than a specific size in graph...
+#
+sub GetNumOfCyclesWithSizeLessThan {
+  my($This, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('GraphCycle', 'SizeLessThan', $CycleSize);
+}
+
+# Get number of cycles with size greater than a specific size in graph...
+#
+sub GetNumOfCyclesWithSizeGreaterThan {
+  my($This, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('GraphCycle', 'SizeGreaterThan', $CycleSize);
+}
+
+# Get largest cyclic path in graph...
+#
+sub GetLargestCycle {
+  my($This) = @_;
+
+  return $This->_GetCycle('GraphCycle', 'LargestCycle');
+}
+
+# Get smallest cyclic path in graph...
+#
+sub GetSmallestCycle {
+  my($This) = @_;
+
+  return $This->_GetCycle('GraphCycle', 'SmallestCycle');
+}
+
+# Get all cycles in graph...
+#
+sub GetCycles {
+  my($This) = @_;
+
+  return $This->_GetCyclesWithSize('GraphCycle', 'AllSizes');
+}
+
+# Get cycles with odd size in graph...
+#
+sub GetCyclesWithOddSize {
+  my($This) = @_;
+
+  return $This->_GetCyclesWithSize('GraphCycle', 'OddSize');
+}
+
+# Get cycles with even size in graph...
+#
+sub GetCyclesWithEvenSize {
+  my($This) = @_;
+
+  return $This->_GetCyclesWithSize('GraphCycle', 'EvenSize');
+}
+
+# Get cycles with specific size in graph...
+#
+sub GetCyclesWithSize {
+  my($This, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('GraphCycle', 'SpecifiedSize', $CycleSize);
+}
+
+# Get cycles with size less than a specific size in graph...
+#
+sub GetCyclesWithSizeLessThan {
+  my($This, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('GraphCycle', 'SizeLessThan', $CycleSize);
+}
+
+# Get cycles with size greater than a specific size in graph...
+#
+sub GetCyclesWithSizeGreaterThan {
+  my($This, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('GraphCycle', 'SizeGreaterThan', $CycleSize);
+}
+
+# Is vertex in a cycle?
+#
+sub IsCyclicVertex {
+  my($This, $VertexID) = @_;
+
+  return $This->GetNumOfVertexCycles($VertexID) ? 1 : 0;
+}
+
+# Is vertex in a only one cycle?
+#
+sub IsUnicyclicVertex {
+  my($This, $VertexID) = @_;
+
+  return ($This->GetNumOfVertexCycles($VertexID)  == 1) ? 1 : 0;
+}
+
+# Is vertex not in a cycle?
+#
+sub IsAcyclicVertex {
+  my($This, $VertexID) = @_;
+
+  return $This->GetNumOfVertexCycles($VertexID) ? 0 : 1;
+}
+
+# Get size of smallest cycle containing specified vertex...
+#
+sub GetSizeOfSmallestVertexCycle {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCycleSize('VertexCycle', 'SmallestCycle', $VertexID);
+}
+
+# Get size of largest cycle containing specified vertex...
+#
+sub GetSizeOfLargestVertexCycle {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCycleSize('VertexCycle', 'LargestCycle', $VertexID);
+}
+
+# Get number of cycles containing specified vertex...
+#
+sub GetNumOfVertexCycles {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('VertexCycle', 'AllSizes', 0, $VertexID);
+}
+
+# Get number of cycles with odd size containing specified vertex...
+#
+sub GetNumOfVertexCyclesWithOddSize {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('VertexCycle', 'OddSize', 0, $VertexID);
+}
+
+# Get number of cycles with even size containing specified vertex...
+#
+sub GetNumOfVertexCyclesWithEvenSize {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('VertexCycle', 'EvenSize', 0, $VertexID);
+}
+
+# Get number of cycles with specified size containing specified vertex...
+#
+sub GetNumOfVertexCyclesWithSize {
+  my($This, $VertexID, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('VertexCycle', 'SpecifiedSize', $CycleSize, $VertexID);
+}
+
+# Get number of cycles with size less than specified size containing specified vertex...
+#
+sub GetNumOfVertexCyclesWithSizeLessThan {
+  my($This, $VertexID, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('VertexCycle', 'SizeLessThan', $CycleSize, $VertexID);
+}
+
+# Get number of cycles with size greater than specified size containing specified vertex...
+#
+sub GetNumOfVertexCyclesWithSizeGreaterThan {
+  my($This, $VertexID, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('VertexCycle', 'SizeGreaterThan', $CycleSize, $VertexID);
+}
+
+# Get smallest cycle containing specified vertex...
+#
+sub GetSmallestVertexCycle {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCycle('VertexCycle', 'SmallestCycle', $VertexID);
+}
+
+# Get largest cycle containing specified vertex...
+#
+sub GetLargestVertexCycle {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCycle('VertexCycle', 'LargestCycle', $VertexID);
+}
+
+# Get cycles containing specified vertex...
+#
+sub GetVertexCycles {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCyclesWithSize('VertexCycle', 'AllSizes', 0, $VertexID);
+}
+
+# Get cycles with odd size containing specified vertex...
+#
+sub GetVertexCyclesWithOddSize {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCyclesWithSize('VertexCycle', 'OddSize', 0, $VertexID);
+}
+
+# Get cycles with even size containing specified vertex...
+#
+sub GetVertexCyclesWithEvenSize {
+  my($This, $VertexID) = @_;
+
+  return $This->_GetCyclesWithSize('VertexCycle', 'EvenSize', 0, $VertexID);
+}
+
+# Get cycles with specified size containing specified vertex...
+#
+sub GetVertexCyclesWithSize {
+  my($This, $VertexID, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('VertexCycle', 'SpecifiedSize', $CycleSize, $VertexID);
+}
+
+# Get cycles with size less than specified size containing specified vertex...
+#
+sub GetVertexCyclesWithSizeLessThan {
+  my($This, $VertexID, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('VertexCycle', 'SizeLessThan', $CycleSize, $VertexID);
+}
+
+# Get cycles with size greater than specified size containing specified vertex...
+#
+sub GetVertexCyclesWithSizeGreaterThan {
+  my($This, $VertexID, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('VertexCycle', 'SizeGreaterThan', $CycleSize, $VertexID);
+}
+
+# Is edge in a cycle?
+#
+sub IsCyclicEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->GetNumOfEdgeCycles($VertexID1, $VertexID2) ? 1 : 0;
+}
+
+# Is edge in a only one cycle?
+#
+sub IsUnicyclicEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return ($This->GetNumOfEdgeCycles($VertexID1, $VertexID2)  == 1) ? 1 : 0;
+}
+
+# Is Edge not in a cycle?
+#
+sub IsAcyclicEdge {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->GetNumOfEdgeCycles($VertexID1, $VertexID2) ? 0 : 1;
+}
+
+# Get size of smallest cycle containing specified edge...
+#
+sub GetSizeOfSmallestEdgeCycle {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCycleSize('EdgeCycle', 'SmallestCycle', $VertexID1, $VertexID2);
+}
+
+# Get size of largest cycle containing specified edge...
+#
+sub GetSizeOfLargestEdgeCycle {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCycleSize('EdgeCycle', 'LargestCycle', $VertexID1, $VertexID2);
+}
+
+# Get number of cycles containing specified edge...
+#
+sub GetNumOfEdgeCycles {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('EdgeCycle', 'AllSizes', 0, $VertexID1, $VertexID2);
+}
+
+# Get number of cycles with odd size containing specified edge...
+#
+sub GetNumOfEdgeCyclesWithOddSize {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('EdgeCycle', 'OddSize', 0, $VertexID1, $VertexID2);
+}
+
+# Get number of cycles with even size containing specified edge...
+#
+sub GetNumOfEdgeCyclesWithEvenSize {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('EdgeCycle', 'EvenSize', 0, $VertexID1, $VertexID2);
+}
+
+# Get number of cycles with specified size containing specified edge...
+#
+sub GetNumOfEdgeCyclesWithSize {
+  my($This, $VertexID1, $VertexID2, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('EdgeCycle', 'SpecifiedSize', $CycleSize, $VertexID1, $VertexID2);
+}
+
+# Get number of cycles with size less than specified size containing specified edge...
+#
+sub GetNumOfEdgeCyclesWithSizeLessThan {
+  my($This, $VertexID1, $VertexID2, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('EdgeCycle', 'SizeLessThan', $CycleSize, $VertexID1, $VertexID2);
+}
+
+# Get number of cycles with size greater than specified size containing specified edge...
+#
+sub GetNumOfEdgeCyclesWithSizeGreaterThan {
+  my($This, $VertexID1, $VertexID2, $CycleSize) = @_;
+
+  return $This->_GetNumOfCyclesWithSize('EdgeCycle', 'SizeGreaterThan', $CycleSize, $VertexID1, $VertexID2);
+}
+
+# Get smallest cycle containing specified edge...
+#
+sub GetSmallestEdgeCycle {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCycle('EdgeCycle', 'SmallestCycle', $VertexID1, $VertexID2);
+}
+
+# Get largest cycle containing specified edge...
+#
+sub GetLargestEdgeCycle {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCycle('EdgeCycle', 'LargestCycle', $VertexID1, $VertexID2);
+}
+
+# Get cycles containing specified edge...
+#
+sub GetEdgeCycles {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCyclesWithSize('EdgeCycle', 'AllSizes', 0, $VertexID1, $VertexID2);
+}
+
+# Get cycles with odd size containing specified edge...
+#
+sub GetEdgeCyclesWithOddSize {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCyclesWithSize('EdgeCycle', 'OddSize', 0, $VertexID1, $VertexID2);
+}
+
+# Get cycles with even size containing specified edge...
+#
+sub GetEdgeCyclesWithEvenSize {
+  my($This, $VertexID1, $VertexID2) = @_;
+
+  return $This->_GetCyclesWithSize('EdgeCycle', 'EvenSize', 0, $VertexID1, $VertexID2);
+}
+
+# Get cycles with specified size containing specified edge...
+#
+sub GetEdgeCyclesWithSize {
+  my($This, $VertexID1, $VertexID2, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('EdgeCycle', 'SpecifiedSize', $CycleSize, $VertexID1, $VertexID2);
+}
+
+# Get cycles with size less than specified size containing specified edge...
+#
+sub GetEdgeCyclesWithSizeLessThan {
+  my($This, $VertexID1, $VertexID2, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('EdgeCycle', 'SizeLessThan', $CycleSize, $VertexID1, $VertexID2);
+}
+
+# Get cycles with size greater than specified size containing specified edge...
+#
+sub GetEdgeCyclesWithSizeGreaterThan {
+  my($This, $VertexID1, $VertexID2, $CycleSize) = @_;
+
+  return $This->_GetCyclesWithSize('EdgeCycle', 'SizeGreaterThan', $CycleSize, $VertexID1, $VertexID2);
+}
+
+# Get size of specified cycle type...
+#
+sub _GetCycleSize {
+  my($This, $Mode, $CycleSize, $VertexID1, $VertexID2) = @_;
+  my($ActiveCyclicPathsRef, $CyclicPath, $Size);
+
+  if (!$This->HasGraphProperty('ActiveCyclicPaths')) {
+    return 0;
+  }
+  if ($Mode =~ /^VertexCycle$/i) {
+    if (!$This->HasVertexProperty('ActiveCyclicPaths', $VertexID1)) {
+      return 0;
+    }
+  }
+  elsif ($Mode =~ /^EdgeCycle$/i) {
+    if (!$This->HasEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2)) {
+      return 0;
+    }
+  }
+
+  MODE: {
+      if ($Mode =~ /^GraphCycle$/i) { $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths'); last MODE; }
+      if ($Mode =~ /^VertexCycle$/i) { $ActiveCyclicPathsRef = $This->GetVertexProperty('ActiveCyclicPaths', $VertexID1); last MODE; }
+      if ($Mode =~ /^EdgeCycle$/i) { $ActiveCyclicPathsRef = $This->GetEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2); last MODE; }
+      return 0;
+  }
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    return 0;
+  }
+
+  CYCLESIZE: {
+      if ($CycleSize =~ /^SmallestCycle$/i) { $CyclicPath = $ActiveCyclicPathsRef->[0]; last CYCLESIZE; }
+      if ($CycleSize =~ /^LargestCycle$/i) { $CyclicPath = $ActiveCyclicPathsRef->[$#{$ActiveCyclicPathsRef}]; last CYCLESIZE; }
+      return 0;
+  }
+  $Size = $CyclicPath->GetLength() - 1;
+
+  return $Size;
+}
+
+# Get of specified cycle size...
+#
+sub _GetCycle {
+  my($This, $Mode, $CycleSize, $VertexID1, $VertexID2) = @_;
+  my($ActiveCyclicPathsRef, $CyclicPath, $Size);
+
+  if (!$This->HasGraphProperty('ActiveCyclicPaths')) {
+    return $This->_GetEmptyCycles();
+  }
+  if ($Mode =~ /^VertexCycle$/i) {
+    if (!$This->HasVertexProperty('ActiveCyclicPaths', $VertexID1)) {
+      return $This->_GetEmptyCycles();
+    }
+  }
+  elsif ($Mode =~ /^EdgeCycle$/i) {
+    if (!$This->HasEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2)) {
+      return $This->_GetEmptyCycles();
+    }
+  }
+
+  MODE: {
+      if ($Mode =~ /^GraphCycle$/i) { $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths'); last MODE; }
+      if ($Mode =~ /^VertexCycle$/i) { $ActiveCyclicPathsRef = $This->GetVertexProperty('ActiveCyclicPaths', $VertexID1); last MODE; }
+      if ($Mode =~ /^EdgeCycle$/i) { $ActiveCyclicPathsRef = $This->GetEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2); last MODE; }
+      return $This->_GetEmptyCycles();
+  }
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    return $This->_GetEmptyCycles();
+  }
+
+  CYCLESIZE: {
+      if ($CycleSize =~ /^SmallestCycle$/i) { $CyclicPath = $ActiveCyclicPathsRef->[0]; last CYCLESIZE; }
+      if ($CycleSize =~ /^LargestCycle$/i) { $CyclicPath = $ActiveCyclicPathsRef->[$#{$ActiveCyclicPathsRef}]; last CYCLESIZE; }
+      return $This->_GetEmptyCycles();
+  }
+  return $CyclicPath;
+}
+
+# Get num of cycles in graph...
+#
+sub _GetNumOfCyclesWithSize {
+  my($This, $Mode, $SizeMode, $SpecifiedSize, $VertexID1, $VertexID2) = @_;
+  my($ActiveCyclicPathsRef);
+
+  if (!$This->HasGraphProperty('ActiveCyclicPaths')) {
+    return 0;
+  }
+  if ($Mode =~ /^VertexCycle$/i) {
+    if (!$This->HasVertexProperty('ActiveCyclicPaths', $VertexID1)) {
+      return 0;
+    }
+  }
+  elsif ($Mode =~ /^EdgeCycle$/i) {
+    if (!$This->HasEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2)) {
+      return 0;
+    }
+  }
+
+  if ($SizeMode =~ /^(SizeLessThan|SizeGreaterThan|SpecifiedSize)$/i) {
+    if (!defined $SpecifiedSize) {
+      carp "Warning: ${ClassName}->_GetNumOfCyclesWithSize: Cycle size muse be defined...";
+      return 0;
+    }
+    if ($SpecifiedSize < 0) {
+      carp "Warning: ${ClassName}->_GetNumOfCyclesWithSize: Specified cycle size, $SpecifiedSize, must be > 0 ...";
+      return 0;
+    }
+  }
+
+  MODE: {
+      if ($Mode =~ /^GraphCycle$/i) { $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths'); last MODE; }
+      if ($Mode =~ /^VertexCycle$/i) { $ActiveCyclicPathsRef = $This->GetVertexProperty('ActiveCyclicPaths', $VertexID1); last MODE; }
+      if ($Mode =~ /^EdgeCycle$/i) { $ActiveCyclicPathsRef = $This->GetEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2); last MODE; }
+      return 0;
+  }
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    return 0;
+  }
+  my($NumOfCycles);
+
+  $NumOfCycles = $This->_GetCycles($Mode, $ActiveCyclicPathsRef, $SizeMode, $SpecifiedSize);
+
+  return $NumOfCycles;
+}
+
+# Get cycles in graph...
+#
+sub _GetCyclesWithSize {
+  my($This, $Mode, $SizeMode, $SpecifiedSize, $VertexID1, $VertexID2) = @_;
+  my($ActiveCyclicPathsRef);
+
+  if (!$This->HasGraphProperty('ActiveCyclicPaths')) {
+    return $This->_GetEmptyCycles();
+  }
+  if ($Mode =~ /^VertexCycle$/i) {
+    if (!$This->HasVertexProperty('ActiveCyclicPaths', $VertexID1)) {
+      return $This->_GetEmptyCycles();
+    }
+  }
+  elsif ($Mode =~ /^EdgeCycle$/i) {
+    if (!$This->HasEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2)) {
+      return $This->_GetEmptyCycles();
+    }
+  }
+
+  if ($SizeMode =~ /^(SizeLessThan|SizeGreaterThan|SpecifiedSize)$/i) {
+    if (!defined $SpecifiedSize) {
+      carp "Warning: ${ClassName}->_GetCyclesWithSize: Cycle size must be defined...";
+      return $This->_GetEmptyCycles();
+    }
+    if ($SpecifiedSize < 0) {
+      carp "Warning: ${ClassName}->_GetCyclesWithSize: Specified cycle size, $SpecifiedSize, must be > 0 ...";
+      return $This->_GetEmptyCycles();
+    }
+  }
+
+  MODE: {
+      if ($Mode =~ /^GraphCycle$/i) { $ActiveCyclicPathsRef = $This->GetGraphProperty('ActiveCyclicPaths'); last MODE; }
+      if ($Mode =~ /^VertexCycle$/i) { $ActiveCyclicPathsRef = $This->GetVertexProperty('ActiveCyclicPaths', $VertexID1); last MODE; }
+      if ($Mode =~ /^EdgeCycle$/i) { $ActiveCyclicPathsRef = $This->GetEdgeProperty('ActiveCyclicPaths', $VertexID1, $VertexID2); last MODE; }
+      return $This->_GetEmptyCycles();
+    }
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    return $This->_GetEmptyCycles();
+  }
+  return $This->_GetCycles($Mode, $ActiveCyclicPathsRef, $SizeMode, $SpecifiedSize);
+}
+
+# Get cycles information...
+#
+sub _GetCycles {
+  my($This, $Mode, $ActiveCyclicPathsRef, $SizeMode, $SpecifiedSize) = @_;
+
+  if (!@{$ActiveCyclicPathsRef}) {
+    return $This->_GetEmptyCycles();
+  }
+
+  if ($SizeMode =~ /^AllSizes$/i) {
+    return wantarray ? @{$ActiveCyclicPathsRef} : scalar @{$ActiveCyclicPathsRef};
+  }
+
+  # Get appropriate cycles...
+  my($Size, $CyclicPath, @FilteredCyclicPaths);
+  @FilteredCyclicPaths = ();
+
+  for $CyclicPath (@{$ActiveCyclicPathsRef}) {
+    $Size = $CyclicPath->GetLength() - 1;
+    SIZEMODE: {
+      if ($SizeMode =~ /^OddSize$/i) { if ($Size % 2) { push @FilteredCyclicPaths, $CyclicPath; } last SIZEMODE; }
+      if ($SizeMode =~ /^EvenSize$/i) { if (!($Size % 2)) { push @FilteredCyclicPaths, $CyclicPath; } last SIZEMODE; }
+      if ($SizeMode =~ /^SizeLessThan$/i) { if ($Size < $SpecifiedSize) { push @FilteredCyclicPaths, $CyclicPath; } last SIZEMODE; }
+      if ($SizeMode =~ /^SizeGreaterThan$/i) { if ($Size > $SpecifiedSize) { push @FilteredCyclicPaths, $CyclicPath; } last SIZEMODE; }
+      if ($SizeMode =~ /^SpecifiedSize$/i) { if ($Size == $SpecifiedSize) { push @FilteredCyclicPaths, $CyclicPath; } last SIZEMODE; }
+      return undef;
+    }
+  }
+  return wantarray ? @FilteredCyclicPaths : scalar @FilteredCyclicPaths;
+}
+
+# Return empty cyles array...
+#
+sub _GetEmptyCycles {
+  my($This) = @_;
+  my(@CyclicPaths);
+
+  @CyclicPaths = ();
+
+  return wantarray ? @CyclicPaths : scalar @CyclicPaths;
+}
+
+# Does graph contains fused cycles?
+sub HasFusedCycles {
+  my($This) = @_;
+
+  return ($This->HasGraphProperty('FusedActiveCyclicPaths')) ? 1 : 0;
+}
+
+# Return a reference to fused cycle sets lists containing references to lists of cyclic path objects
+# in each fused cycle set and a reference to a list containing non-fused cyclic paths...
+#
+sub GetFusedAndNonFusedCycles {
+  my($This) = @_;
+  my($FusedCycleSetsRef, $NonFusedCyclesRef);
+
+  $FusedCycleSetsRef = $This->HasGraphProperty('FusedActiveCyclicPaths') ? $This->GetGraphProperty('FusedActiveCyclicPaths') : undef;
+  $NonFusedCyclesRef = $This->HasGraphProperty('NonFusedActiveCyclicPaths') ? $This->GetGraphProperty('NonFusedActiveCyclicPaths') : undef;
+
+  return ($FusedCycleSetsRef, $NonFusedCyclesRef);
+}
+
+# Get vertices of connected components as a list containing references to
+# lists of vertices for each component  sorted in order of its decreasing size...
+#
+sub GetConnectedComponentsVertices {
+  my($This) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformDepthFirstSearch();
+
+  return $PathsTraversal->GetConnectedComponentsVertices();
+}
+
+# Get a list of topologically sorted vertrices starting from a specified vertex or
+# an arbitrary vertex in the graph...
+#
+sub GetTopologicallySortedVertices {
+  my($This, $RootVertexID) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformBreadthFirstSearch($RootVertexID);
+
+  return $PathsTraversal->GetVertices();
+}
+
+# Get a list of paths starting from a specified vertex with length upto specified length
+# and no sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetPathsStartingAtWithLengthUpto {
+  my($This, $StartVertexID, $Length, $AllowCycles) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformPathsSearchWithLengthUpto($StartVertexID, $Length, $AllowCycles);
+
+  return $PathsTraversal->GetPaths();
+}
+
+# Get a list of paths starting from a specified vertex with specified length
+# and no sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetPathsStartingAtWithLength {
+  my($This, $StartVertexID, $Length, $AllowCycles) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformPathsSearchWithLength($StartVertexID, $Length, $AllowCycles);
+
+  return $PathsTraversal->GetPaths();
+}
+
+# Get a list of paths with all possible lengths starting from a specified vertex
+# with no sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetPathsStartingAt {
+  my($This, $StartVertexID, $AllowCycles) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformPathsSearch($StartVertexID, $AllowCycles);
+
+  return $PathsTraversal->GetPaths();
+}
+
+# Get a list of all paths starting from a specified vertex with length upto a specified length
+# with sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetAllPathsStartingAtWithLengthUpto {
+  my($This, $StartVertexID, $Length, $AllowCycles) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformAllPathsSearchWithLengthUpto($StartVertexID, $Length, $AllowCycles);
+
+  return $PathsTraversal->GetPaths();
+}
+
+# Get a list of all paths starting from a specified vertex with specified length
+# with sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetAllPathsStartingAtWithLength {
+  my($This, $StartVertexID, $Length, $AllowCycles) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformAllPathsSearchWithLength($StartVertexID, $Length, $AllowCycles);
+
+  return $PathsTraversal->GetPaths();
+}
+
+
+# Get a list of all paths with all possible lengths starting from a specified vertex
+# with sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetAllPathsStartingAt {
+  my($This, $StartVertexID, $AllowCycles) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformAllPathsSearch($StartVertexID, $AllowCycles);
+
+  return $PathsTraversal->GetPaths();
+}
+
+# Get a reference to list of paths starting from each vertex in graph with length upto specified
+# length and no sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetPathsWithLengthUpto {
+  my($This, $Length, $AllowCycles) = @_;
+
+  $AllowCycles = (defined $AllowCycles) ? $AllowCycles : 1;
+
+  return $This->_GetPaths('PathsWithLengthUpto', $Length, $AllowCycles);
+}
+
+# Get a reference to list of paths starting from each vertex in graph with specified
+# length and no sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+sub GetPathsWithLength {
+  my($This, $Length, $AllowCycles) = @_;
+
+  $AllowCycles = (defined $AllowCycles) ? $AllowCycles : 1;
+
+  return $This->_GetPaths('PathsWithLength', $Length, $AllowCycles);
+}
+
+# Get a reference to list of paths with all possible lengths starting from each vertex
+# with no sharing of edges in paths traversed. By default, cycles are included in paths.
+# A path containing a cycle is terminated at a vertex completing the cycle.
+#
+#
+sub GetPaths {
+  my($This, $AllowCycles) = @_;
+
+  $AllowCycles = (defined $AllowCycles) ? $AllowCycles : 1;
+
+  return $This->_GetPaths('PathsWithAllLengths', undef, $AllowCycles);
+}
+
+# Get a reference to list of all paths starting from each vertex in graph with length upto a specified
+# length with sharing of edges in paths traversed. By default, cycles are included in paths. A path
+# containing a cycle is terminated at a vertex completing the cycle.
+#
+# Note:
+#   . Duplicate paths are not removed.
+#
+sub GetAllPathsWithLengthUpto {
+  my($This, $Length, $AllowCycles) = @_;
+
+  $AllowCycles = (defined $AllowCycles) ? $AllowCycles : 1;
+
+  return $This->_GetPaths('AllPathsWithLengthUpto', $Length, $AllowCycles);
+}
+
+# Get a reference to list of all paths starting from each vertex in graph with specified
+# length with sharing of edges in paths traversed. By default, cycles are included in paths. A path
+# containing a cycle is terminated at a vertex completing the cycle.
+#
+# Note:
+#   . Duplicate paths are not removed.
+#
+sub GetAllPathsWithLength {
+  my($This, $Length, $AllowCycles) = @_;
+
+  $AllowCycles = (defined $AllowCycles) ? $AllowCycles : 1;
+
+  return $This->_GetPaths('AllPathsWithLength', $Length, $AllowCycles);
+}
+
+# Get a reference to list of all paths with all possible lengths starting from each vertex in graph
+# with sharing of edges in paths traversed. By default, cycles are included in paths. A path
+# containing a cycle is terminated at a vertex completing the cycle.
+#
+# Note:
+#   . Duplicate paths are not removed.
+#
+sub GetAllPaths {
+  my($This, $AllowCycles) = @_;
+
+  $AllowCycles = (defined $AllowCycles) ? $AllowCycles : 1;
+
+  return $This->_GetPaths('AllPathsWithAllLengths', undef, $AllowCycles);
+}
+
+
+# Retrieve appropriate paths for each vertex in graph and return a referernce to list
+# containing path objects...
+#
+sub _GetPaths {
+  my($This, $Mode, $Length, $AllowCycles) = @_;
+  my($VertexID, @EmptyPaths, @Paths);
+
+  @Paths = (); @EmptyPaths = ();
+
+  for $VertexID ($This->GetVertices()) {
+    my($Status, $PathsTraversal);
+
+    $PathsTraversal = new Graph::PathsTraversal($This);
+    MODE: {
+      if ($Mode =~ /^PathsWithLengthUpto$/i) { $Status = $PathsTraversal->PerformPathsSearchWithLengthUpto($VertexID, $Length, $AllowCycles); last MODE; }
+      if ($Mode =~ /^PathsWithLength$/i) { $Status = $PathsTraversal->PerformPathsSearchWithLength($VertexID, $Length, $AllowCycles); last MODE; }
+      if ($Mode =~ /^PathsWithAllLengths$/i) { $Status = $PathsTraversal->PerformPathsSearch($VertexID, $AllowCycles); last MODE; }
+
+      if ($Mode =~ /^AllPathsWithLengthUpto$/i) { $Status = $PathsTraversal->PerformAllPathsSearchWithLengthUpto($VertexID, $Length, $AllowCycles); last MODE; }
+      if ($Mode =~ /^AllPathsWithLength$/i) { $Status = $PathsTraversal->PerformAllPathsSearchWithLength($VertexID, $Length, $AllowCycles); last MODE; }
+      if ($Mode =~ /^AllPathsWithAllLengths$/i) { $Status = $PathsTraversal->PerformAllPathsSearch($VertexID, $AllowCycles); last MODE; }
+
+      return \@EmptyPaths;
+    }
+    if (!defined $Status) {
+      return \@EmptyPaths;
+    }
+    push @Paths, $PathsTraversal->GetPaths();
+  }
+  return \@Paths;
+}
+
+# Get a list of paths between two vertices. For cyclic graphs, the list contains
+# may contain two paths...
+#
+sub GetPathsBetween {
+  my($This, $StartVertexID, $EndVertexID) = @_;
+  my($Path, $ReversePath, @Paths);
+
+  @Paths = ();
+
+  $Path = $This->_GetPathBetween($StartVertexID, $EndVertexID);
+  if (!defined $Path) {
+    return \@Paths;
+  }
+
+  $ReversePath = $This->_GetPathBetween($EndVertexID, $StartVertexID);
+  if (!defined $ReversePath) {
+    return \@Paths;
+  }
+  if ($Path eq $ReversePath) {
+    push @Paths, $Path;
+  }
+  else {
+    # Make sure first vertex in reverse path corresponds to specified start vertex ID...
+    $ReversePath->Reverse();
+    push @Paths, ($Path->GetLength <= $ReversePath->GetLength()) ? ($Path, $ReversePath) : ($ReversePath, $Path);
+  }
+  return @Paths;
+}
+
+# Get a path beween two vertices...
+#
+sub _GetPathBetween {
+  my($This, $StartVertexID, $EndVertexID) = @_;
+  my($PathsTraversal,  @Paths);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformPathsSearchBetween($StartVertexID, $EndVertexID);
+
+  @Paths = $PathsTraversal->GetPaths();
+
+  return (@Paths) ? $Paths[0] : undef;
+}
+
+# Get a list containing lists of neighborhood vertices around a specified vertex with in a
+# specified radius...
+#
+sub GetNeighborhoodVerticesWithRadiusUpto {
+  my($This, $StartVertexID, $Radius) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformNeighborhoodVerticesSearchWithRadiusUpto($StartVertexID, $Radius);
+
+  return $PathsTraversal->GetVerticesNeighborhoods();
+}
+
+# Get a list containing lists of neighborhood vertices around a specified vertex at all
+# radii levels...
+#
+sub GetNeighborhoodVertices {
+  my($This, $StartVertexID) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformNeighborhoodVerticesSearch($StartVertexID);
+
+  return $PathsTraversal->GetVerticesNeighborhoods();
+}
+
+# Get neighborhood vertices around a specified vertex, along with their successor connected vertices, collected
+# with in a specified radius as a list containing references to lists with first value corresponding to vertex
+# ID and second value as reference to a list containing its successor connected vertices.
+#
+# For a neighborhood vertex at each radius level, the successor connected vertices correspond to the
+# neighborhood vertices at the next radius level. Consequently, the neighborhood vertices at the last
+# radius level don't contain any successor vertices which fall outside the range of specified radius.
+#
+sub GetNeighborhoodVerticesWithSuccessorsAndRadiusUpto {
+  my($This, $StartVertexID, $Radius) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformNeighborhoodVerticesSearchWithSuccessorsAndRadiusUpto($StartVertexID, $Radius);
+
+  return $PathsTraversal->GetVerticesNeighborhoodsWithSuccessors();
+}
+
+# Get neighborhood vertices around a specified vertex, along with their successor connected vertices, collected
+# at all neighborhood radii as a list containing references to lists with first value corresponding to vertex
+# ID and second value as reference to a list containing its successor connected vertices.
+#
+# For a neighborhood vertex at each radius level, the successor connected vertices correspond to the
+# neighborhood vertices at the next radius level. Consequently, the neighborhood vertices at the last
+# radius level don't contain any successor vertices which fall outside the range of specified radius.
+#
+sub GetNeighborhoodVerticesWithSuccessors {
+  my($This, $StartVertexID) = @_;
+  my($PathsTraversal);
+
+  $PathsTraversal = new Graph::PathsTraversal($This);
+  $PathsTraversal->PerformNeighborhoodVerticesSearchWithSuccessors($StartVertexID);
+
+  return $PathsTraversal->GetVerticesNeighborhoodsWithSuccessors();
+}
+
+# Get adjacency matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+# For a simple graph G with n vertices, the adjacency matrix for G is a n x n square matrix and
+# its elements Mij are:
+#
+#   . 0    if i == j
+#   . 1    if i != j and vertex Vi is adjacent to vertex Vj
+#   . 0    if i != j and vertex Vi is not adjacent to vertex Vj
+#
+sub GetAdjacencyMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateAdjacencyMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get Siedel adjacency matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+# For a simple graph G with n vertices, the Siedal adjacency matrix for G is a n x n square matrix and
+# its elements Mij are:
+#
+#   . 0    if i == j
+#   . -1   if i != j and vertex Vi is adjacent to vertex Vj
+#   . 1    if i != j and vertex Vi is not adjacent to vertex Vj
+#
+sub GetSiedelAdjacencyMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateSiedelAdjacencyMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get distance matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+# For a simple graph G with n vertices, the distance matrix for G is a n x n square matrix and
+# its elements Mij are:
+#
+#   . 0    if i == j
+#   . d    if i != j and d is the shortest distance between vertex Vi and vertex Vj
+#
+# Note:
+#   . In the final matrix, BigNumber values correspond to vertices with no edges.
+#
+sub GetDistanceMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateDistanceMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get incidence matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices and edges returned by GetVertices and GetEdges
+# methods respectively.
+#
+# For a simple graph G with n vertices and e edges, the incidence matrix for G is a n x e matrix
+# its elements Mij are:
+#
+#   . 1    if vertex Vi and the edge Ej are incident; in other words, Vi and Ej are related
+#   . 0    otherwise
+#
+sub GetIncidenceMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateIncidenceMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get degree matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+# For a simple graph G with n vertices, the degree matrix for G is a n x n square matrix and
+# its elements Mij are:
+#
+#   . deg(Vi)   if i == j and deg(Vi) is the degree of vertex Vi
+#   . 0         otherwise
+#
+sub GetDegreeMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateDegreeMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get Laplacian matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+# For a simple graph G with n vertices, the Laplacian matrix for G is a n x n square matrix and
+# its elements Mij are:
+#
+#   . deg(Vi)   if i == j and deg(Vi) is the degree of vertex Vi
+#   . -1        if i != j and vertex Vi is adjacent to vertex Vj
+#   . 0         otherwise
+#
+# Note: The Laplacian matrix is the difference between the degree matrix and adjacency matrix.
+#
+sub GetLaplacianMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateLaplacianMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get normalized Laplacian matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+# For a simple graph G with n vertices, the normalized Laplacian matrix L for G is a n x n square matrix and
+# its elements Lij are:
+#
+#   . 1                           if i == j and deg(Vi) != 0
+#   . -1/SQRT(deg(Vi) * deg(Vj))  if i != j and vertex Vi is adjacent to vertex Vj
+#   . 0                           otherwise
+#
+#
+sub GetNormalizedLaplacianMatrix {
+  my($This) = @_;
+  my($GraphMatrix);
+
+  $GraphMatrix = new Graph::GraphMatrix($This);
+  $GraphMatrix->GenerateNormalizedLaplacianMatrix();
+
+  return $GraphMatrix->GetMatrix();
+}
+
+# Get admittance matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+sub GetAdmittanceMatrix {
+  my($This) = @_;
+
+  return $This->GetLaplacianMatrix();
+}
+
+# Get Kirchhoff matrix for the graph as a Matrix object with row and column indices
+# corresponding to graph vertices returned by GetVertices method.
+#
+sub GetKirchhoffMatrix {
+  my($This) = @_;
+
+  return $This->GetLaplacianMatrix();
+}
+
+1;
+
+__END__
+
+=head1 NAME
+
+Graph
+
+=head1 SYNOPSIS
+
+use Graph;
+
+use Graph qw(:all);
+
+=head1 DESCRIPTION
+
+B<Graph> class provides the following methods:
+
+new, AddCycle, AddEdge, AddEdges, AddPath, AddVertex, AddVertices, ClearCycles,
+Copy, CopyEdgesProperties, CopyVerticesAndEdges, CopyVerticesProperties,
+DeleteCycle, DeleteEdge, DeleteEdgeProperties, DeleteEdgeProperty, DeleteEdges,
+DeleteEdgesProperties, DeleteEdgesProperty, DeleteGraphProperties,
+DeleteGraphProperty, DeletePath, DeleteVertex, DeleteVertexProperties,
+DeleteVertexProperty, DeleteVertices, DeleteVerticesProperty, DetectCycles,
+GetAdjacencyMatrix, GetAdmittanceMatrix, GetAllPaths, GetAllPathsStartingAt,
+GetAllPathsStartingAtWithLength, GetAllPathsStartingAtWithLengthUpto,
+GetAllPathsWithLength, GetAllPathsWithLengthUpto, GetCircumference,
+GetConnectedComponentsVertices, GetCycles, GetCyclesWithEvenSize,
+GetCyclesWithOddSize, GetCyclesWithSize, GetCyclesWithSizeGreaterThan,
+GetCyclesWithSizeLessThan, GetDegree, GetDegreeMatrix, GetDistanceMatrix,
+GetEdgeCycles, GetEdgeCyclesWithEvenSize, GetEdgeCyclesWithOddSize,
+GetEdgeCyclesWithSize, GetEdgeCyclesWithSizeGreaterThan,
+GetEdgeCyclesWithSizeLessThan, GetEdgeProperties, GetEdgeProperty, GetEdges,
+GetEdgesProperty, GetFusedAndNonFusedCycles, GetGirth, GetGraphProperties,
+GetGraphProperty, GetIncidenceMatrix, GetIsolatedVertices, GetKirchhoffMatrix,
+GetLaplacianMatrix, GetLargestCycle, GetLargestEdgeCycle, GetLargestVertexCycle,
+GetLeafVertices, GetMaximumDegree, GetMininumDegree, GetNeighborhoodVertices,
+GetNeighborhoodVerticesWithRadiusUpto, GetNeighborhoodVerticesWithSuccessors,
+GetNeighborhoodVerticesWithSuccessorsAndRadiusUpto, GetNeighbors,
+GetNormalizedLaplacianMatrix, GetNumOfCycles, GetNumOfCyclesWithEvenSize,
+GetNumOfCyclesWithOddSize, GetNumOfCyclesWithSize,
+GetNumOfCyclesWithSizeGreaterThan, GetNumOfCyclesWithSizeLessThan,
+GetNumOfEdgeCycles, GetNumOfEdgeCyclesWithEvenSize, GetNumOfEdgeCyclesWithOddSize,
+GetNumOfEdgeCyclesWithSize, GetNumOfEdgeCyclesWithSizeGreaterThan,
+GetNumOfEdgeCyclesWithSizeLessThan, GetNumOfVertexCycles,
+GetNumOfVertexCyclesWithEvenSize, GetNumOfVertexCyclesWithOddSize,
+GetNumOfVertexCyclesWithSize, GetNumOfVertexCyclesWithSizeGreaterThan,
+GetNumOfVertexCyclesWithSizeLessThan, GetPaths, GetPathsBetween,
+GetPathsStartingAt, GetPathsStartingAtWithLength,
+GetPathsStartingAtWithLengthUpto, GetPathsWithLength, GetPathsWithLengthUpto,
+GetSiedelAdjacencyMatrix, GetSizeOfLargestCycle, GetSizeOfLargestEdgeCycle,
+GetSizeOfLargestVertexCycle, GetSizeOfSmallestCycle, GetSizeOfSmallestEdgeCycle,
+GetSizeOfSmallestVertexCycle, GetSmallestCycle, GetSmallestEdgeCycle,
+GetSmallestVertexCycle, GetTopologicallySortedVertices, GetVertex,
+GetVertexCycles, GetVertexCyclesWithEvenSize, GetVertexCyclesWithOddSize,
+GetVertexCyclesWithSize, GetVertexCyclesWithSizeGreaterThan,
+GetVertexCyclesWithSizeLessThan, GetVertexProperties, GetVertexProperty,
+GetVertexWithLargestDegree, GetVertexWithSmallestDegree, GetVertices,
+GetVerticesProperty, GetVerticesWithDegreeLessThan, HasCycle, HasEdge,
+HasEdgeProperty, HasEdges, HasFusedCycles, HasGraphProperty, HasPath, HasVertex,
+HasVertexProperty, HasVertices, IsAcyclic, IsAcyclicEdge, IsAcyclicVertex,
+IsCyclic, IsCyclicEdge, IsCyclicVertex, IsGraph, IsIsolatedVertex, IsLeafVertex,
+IsUnicyclic, IsUnicyclicEdge, IsUnicyclicVertex, SetActiveCyclicPaths,
+SetEdgeProperties, SetEdgeProperty, SetEdgesProperty, SetGraphProperties,
+SetGraphProperty, SetVertexProperties, SetVertexProperty, SetVerticesProperty,
+StringifyEdgesProperties, StringifyGraph, StringifyGraphProperties,
+StringifyProperties, StringifyVerticesAndEdges, StringifyVerticesProperties,
+UpdateEdgeProperty, UpdateVertexProperty
+
+=head2 METHODS
+
+=over 4
+
+=item B<new>
+
+    $NewGraph = new Graph([@VertexIDs]);
+
+Using specified I<Graph> I<VertexIDs>, B<new> method creates a new B<Graph> object and returns
+newly created B<Graph> object.
+
+Examples:
+
+    $Graph = new Graph();
+    $Graph = new Graph(@VertexIDs);
+
+=item B<AddCycle>
+
+    $Graph->AddCycle(@VertexIDs);
+
+Adds edges between successive pair of I<VertexIDs> including an additional edge from the last
+to first vertex ID to complete the cycle to I<Graph> and returns I<Graph>.
+
+=item B<AddEdge>
+
+    $Graph->AddEdge($VertexID1, $VertexID2);
+
+Adds an edge between I<VertexID1> and I<VertexID2> in a I<Graph> and returns I<Graph>.
+
+=item B<AddEdges>
+
+    $Graph->AddEdges(@VertexIDs);
+
+Adds edges between successive pair of I<VertexIDs> in a I<Graph> and returns I<Graph>.
+
+=item B<AddPath>
+
+    $Graph->AddPath(@VertexIDs);
+
+Adds edges between successive pair of I<VertexIDs> in a I<Graph> and returns I<Graph>.
+
+=item B<AddVertex>
+
+    $Graph->AddVertex($VertexID);
+
+Adds I<VertexID> to I<Graph> and returns I<Graph>.
+
+=item B<AddVertices>
+
+    $Graph->AddVertices(@VertexIDs);
+
+Adds vertices using I<VertexIDs> to I<Graph> and returns I<Graph>.
+
+=item B<ClearCycles>
+
+    $Graph->ClearCycles();
+
+Delete all cycle properties assigned to graph, vertices, and edges by I<DetectCycles> method.
+
+=item B<Copy>
+
+    $NewGraph = $Graph->Copy();
+
+Copies I<Graph> and its associated data using B<Storable::dclone> and returns a new
+B<Graph> object.
+
+=item B<CopyEdgesProperties>
+
+    $OtherGraph = $Graph->CopyEdgesProperties($OtherGraph);
+
+Copies all properties associated with edges from I<Graph> to I<$OtherGraph> and
+returns I<OtherGraph>.
+
+=item B<CopyVerticesAndEdges>
+
+    $OtherGraph = $Graph->CopyVerticesAndEdges($OtherGraph);
+
+Copies all vertices and edges from I<Graph> to I<$OtherGraph> and returns I<OtherGraph>.
+
+=item B<CopyVerticesProperties>
+
+    $OtherGraph = $Graph->CopyVerticesProperties($OtherGraph);
+
+Copies all properties associated with vertices from I<Graph> to I<$OtherGraph> and
+returns I<OtherGraph>.
+
+=item B<DeleteCycle>
+
+    $Graph->DeleteCycle(@VertexIDs);
+
+Deletes edges between successive pair of I<VertexIDs> including an additional edge from the last
+to first vertex ID to complete the cycle to I<Graph> and returns I<Graph>.
+
+=item B<DeleteEdge>
+
+    $Graph->DeleteEdge($VertexID1, $VertexID2);
+
+Deletes an edge between I<VertexID1> and I<VertexID2> in a I<Graph> and returns I<Graph>.
+
+=item B<DeleteEdgeProperties>
+
+    $Graph->DeleteEdgeProperties($VertexID1, $VertexID2);
+
+Deletes all properties associated with edge between I<VertexID1> and I<VertexID2> in a I<Graph>
+and returns I<Graph>.
+
+=item B<DeleteEdgeProperty>
+
+    $Graph->DeleteEdgeProperty($PropertyName, $VertexID1, $VertexID2);
+
+Deletes I<PropertyName> associated with edge between I<VertexID1> and I<VertexID2> in a I<Graph>
+and returns I<Graph>.
+
+=item B<DeleteEdges>
+
+    $Graph->DeleteEdges(@VertexIDs);
+
+Deletes edges between successive pair of I<VertexIDs> and returns I<Graph>.
+
+=item B<DeleteEdgesProperties>
+
+    $Graph->DeleteEdgesProperties(@VertexIDs);
+
+Deletes all properties associated with edges between successive pair of I<VertexIDs> and
+returns I<Graph>.
+
+=item B<DeleteEdgesProperty>
+
+    $Graph->DeleteEdgesProperty($PropertyName, @VertexIDs);
+
+Deletes I<PropertyName> associated with edges between successive pair of I<VertexIDs>
+and returns I<Graph>.
+
+=item B<DeleteGraphProperties>
+
+    $Graph->DeleteGraphProperties();
+
+Deletes all properties associated as graph not including properties associated to vertices
+or edges and returns I<Graph>.
+
+=item B<DeleteGraphProperty>
+
+    $Graph->DeleteGraphProperty($PropertyName);
+
+Deletes a I<PropertyName> associated as graph property and returns I<Graph>.
+
+=item B<DeletePath>
+
+    $Graph->DeletePath(@VertexIDs);
+
+Deletes edges between successive pair of I<VertexIDs> in a I<Graph> and returns I<Graph>.
+
+=item B<DeleteVertex>
+
+    $Graph->DeleteVertex($VertexID);
+
+Deletes I<VertexID> to I<Graph> and returns I<Graph>.
+
+=item B<DeleteVertexProperties>
+
+    $Graph->DeleteVertexProperties($VertexID);
+
+Deletes all properties associated with I<VertexID> and returns I<Graph>.
+
+=item B<DeleteVertexProperty>
+
+    $Graph->DeleteVertexProperty($PropertyName, $VertexID);
+
+Deletes a I<PropertyName> associated with I<VertexID> and returns I<Graph>.
+
+=item B<DeleteVertices>
+
+    $Graph->DeleteVertices(@VertexIDs);
+
+Deletes vertices specified in I<VertexIDs> and returns I<Graph>.
+
+=item B<DeleteVerticesProperty>
+
+    $Graph->DeleteVerticesProperty($PropertyName, @VertexIDs);
+
+Deletes a I<PropertyName> associated with I<VertexIDs> and returns I<Graph>.
+
+=item B<DetectCycles>
+
+    $Graph->DetectCycles();
+
+Detect cycles using B<CyclesDetection> class and associate found cycles to I<Graph>
+object as graph properties: I<ActiveCyclicPaths, AllCyclicPaths, IndependentCyclicPaths>.
+
+Notes:
+
+    . CyclesDetection class detects all cycles in the graph and filters
+      them to find independent cycles.
+    . All cycles related methods in the graph operate on
+      ActiveCyclicPaths. By default, active cyclic paths correspond
+      to IndependentCyclicPaths. This behavior can be changed
+      using SetActiveCyclicPaths method.
+
+=item B<GetAdjacencyMatrix>
+
+    $GraphMatrix = $Graph->GetAdjacencyMatrix();
+
+Returns adjacency matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the adjacency matrix for G is a n x n square matrix and
+its elements Mij are:
+
+    . 0    if i == j
+    . 1    if i != j and vertex Vi is adjacent to vertex Vj
+    . 0    if i != j and vertex Vi is not adjacent to vertex Vj
+
+=item B<GetAdmittanceMatrix>
+
+    $GraphMatrix = $Graph->GetAdmittanceMatrix();
+
+Returns admittance matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the adjacency matrix for G is a n x n square matrix and
+its elements Mij are:
+
+    . 0    if i == j
+    . 1    if i != j and vertex Vi is adjacent to vertex Vj
+    . 0    if i != j and vertex Vi is not adjacent to vertex Vj
+
+=item B<GetAllPaths>
+
+    $PathsRef = $Graph->GetAllPaths([$AllowCycles]);
+
+Returns a reference to an array containing B<Path> objects corresponding to all possible
+lengths starting from each vertex in graph with sharing of edges in paths traversed.
+By default, cycles are included in paths. A path containing a cycle is terminated at a vertex
+completing the cycle. Duplicate paths are not removed.
+
+=item B<GetAllPathsStartingAt>
+
+    @Paths = $Graph->GetAllPathsStartingAt($StartVertexID,
+             [$AllowCycles]);
+
+Returns an array of I<Path> objects starting from a I<StartVertexID> of any length
+with sharing of edges in paths traversed. By default, cycles are included in paths.
+A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetAllPathsStartingAtWithLength>
+
+    @Paths = $Graph->GetAllPathsStartingAtWithLength($StartVertexID,
+             $Length, [$AllowCycles]);
+
+Returns an array of I<Path> objects starting from a I<StartVertexID> of specified I<Length>
+with sharing of edges in paths traversed. By default, cycles are included in paths.
+A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetAllPathsStartingAtWithLengthUpto>
+
+    @Paths = $Graph->GetAllPathsStartingAtWithLengthUpto($StartVertexID,
+             $Length, [$AllowCycles]);
+
+Returns an array of I<Path> objects starting from a I<StartVertexID> with length upto a
+I<Length> with sharing of edges in paths traversed. By default, cycles are included in paths.
+A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetAllPathsWithLength>
+
+    $PathsRef = $Graph->GetAllPathsWithLength($Length,
+                [$AllowCycles]);
+
+Returns a reference to an array containing B<Path> objects corresponding to paths with
+I<Length> starting from each vertex in graph with sharing of edges in paths traversed.
+By default, cycles are included in paths. A path containing a cycle is terminated at a vertex
+completing the cycle. Duplicate paths are not removed.
+
+=item B<GetAllPathsWithLengthUpto>
+
+    $PathsRef = $Graph->GetAllPathsWithLengthUpto($Length,
+                [$AllowCycles]);
+
+Returns a reference to an array containing B<Path> objects corresponding to paths up to
+specified I<Length> starting from each vertex in graph with sharing of edges in paths traversed.
+By default, cycles are included in paths. A path containing a cycle is terminated at a vertex
+completing the cycle. Duplicate paths are not removed.
+
+=item B<GetCircumference>
+
+    $Circumference = $Graph->GetCircumference();
+
+Returns size of largest cycle in a I<Graph>
+
+=item B<GetConnectedComponentsVertices>
+
+    @ConnectedComponents = $Graph->GetConnectedComponentsVertices();
+
+Returns an array I<ConnectedComponents> containing referecens to arrays with vertex
+IDs for each component sorted in order of their decreasing size.
+
+=item B<GetCycles>
+
+    @CyclicPaths = $Graphs->GetCycles();
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles
+in a I<Graph>.
+
+=item B<GetCyclesWithEvenSize>
+
+    @CyclicPaths = $Graph->GetCyclesWithEvenSize();
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+even size in a I<Graph>.
+
+=item B<GetCyclesWithOddSize>
+
+    @CyclicPaths = $Graph->GetCyclesWithOddSize();
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+odd size in a I<Graph>.
+
+=item B<GetCyclesWithSize>
+
+    @CyclicPaths = $Graph->GetCyclesWithSize($CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+I<CycleSize> in a I<Graph>.
+
+=item B<GetCyclesWithSizeGreaterThan>
+
+    @CyclicPaths = $Graph->GetCyclesWithSizeGreaterThan($CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size greater than I<CycleSize> in a I<Graph>.
+
+=item B<GetCyclesWithSizeLessThan>
+
+    @CyclicPaths = $Graph->GetCyclesWithSizeGreaterThan($CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size less than I<CycleSize> in a I<Graph>.
+
+=item B<GetDegree>
+
+    $Degree = $Graph->GetDegree($VertexID);
+
+Returns B<Degree> for I<VertexID> in a I<Graph> corresponding to sum of in and out vertex
+degree values.
+
+=item B<GetDegreeMatrix>
+
+    $GraphMatrix = $Graph->GetDegreeMatrix();
+
+Returns degree matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the degree matrix for G is a n x n square matrix and
+its elements Mij are:
+
+    . deg(Vi)   if i == j and deg(Vi) is the degree of vertex Vi
+    . 0         otherwise
+
+=item B<GetDistanceMatrix>
+
+    $GraphMatrix = $Graph->GetDistanceMatrix();
+
+Returns distance matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the distance matrix for G is a n x n square matrix and
+its elements Mij are:
+
+    . 0    if i == j
+    . d    if i != j and d is the shortest distance between vertex Vi and vertex Vj
+
+In the final matrix, value of constant B<BigNumber> defined in B<Constants.pm> module
+corresponds to vertices with no edges.
+
+=item B<GetEdgeCycles>
+
+    @CyclicPaths = $Graph->GetEdgeCycles($VertexID1, $VertexID2);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to all cycles containing
+edge between I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetEdgeCyclesWithEvenSize>
+
+    @CyclicPaths = $Graph->GetEdgeCyclesWithEvenSize($VertexID1,
+                   $VertexID2);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+even size containing edge between I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetEdgeCyclesWithOddSize>
+
+    @CyclicPaths = $Graph->GetEdgeCyclesWithOddSize($VertexID1,
+                   $VertexID2);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+odd size containing edge between I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetEdgeCyclesWithSize>
+
+    @CyclicPaths = $Graph->GetEdgeCyclesWithSize($VertexID1, $VertexID2,
+                   $CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size I<CycleSize> containing edge between I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetEdgeCyclesWithSizeGreaterThan>
+
+    @CyclicPaths = $Graph->GetEdgeCyclesWithSizeGreaterThan($VertexID1,
+                   $VertexID2, $CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size greater than I<CycleSize> containing edge between I<VertexID1> and I<VertexID2>
+in a I<Graph>.
+
+=item B<GetEdgeCyclesWithSizeLessThan>
+
+    @CyclicPaths = $Graph->GetEdgeCyclesWithSizeLessThan($VertexID1,
+                   $VertexID2, $CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size less than I<CycleSize> containing edge between I<VertexID1> and I<VertexID2>.
+
+=item B<GetEdgeProperties>
+
+    %EdgeProperties = $Graph->GetEdgeProperties($VertexID1, $VertexID2);
+
+Returns a hash B<EdgeProperties> containing all B<PropertyName> and B<PropertyValue>
+pairs associated with an edge between I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetEdgeProperty>
+
+    $Value = $Graph->GetEdgeProperty($PropertyName, $VertexID1, $VertexID2);
+
+Returns value of I<PropertyName> associated with an edge between I<VertexID1>
+and I<VertexID2> in a I<Graph>.
+
+=item B<GetEdges>
+
+    @EdgeVertexIDs = $Graph->GetEdges($VertexID);
+    $NumOfEdges = $Graph->GetEdges($VertexID);
+
+Returns an array I<EdgeVertexIDs> with successive pair of IDs corresponding to edges involving
+I<VertexID> or number of edges for I<VertexID> in a I<Graph>.
+
+=item B<GetEdgesProperty>
+
+    @PropertyValues = $Graph->GetEdgesProperty($PropertyName, @VertexIDs);
+
+Returns an array I<PropertyValues> containing property values corresponding to
+I<PropertyName> associated with edges between successive pair of I<VertexIDs>.
+
+=item B<GetFusedAndNonFusedCycles>
+
+    ($FusedCycleSetsRef, $NonFusedCyclesRef) =
+       $Graph->GetFusedAndNonFusedCycles();
+
+Returns references to arrays I<FusedCycleSetsRef> and I<NonFusedCyclesRef>
+containing references to arrays of cyclic I<Path> objects corresponding to fuses and
+non-fused cyclic paths.
+
+=item B<GetGirth>
+
+    $Girth = $Graph->GetGirth();
+
+Returns size of smallest cycle in a I<Graph>.
+
+=item B<GetGraphProperties>
+
+    %GraphProperties = $Graph->GetGraphProperties();
+
+Returns a hash B<EdgeProperties> containing all B<PropertyName> and B<PropertyValue>
+pairs associated with graph in a I<Graph>.
+
+=item B<GetGraphProperty>
+
+    $PropertyValue = $Graph->GetGraphProperty($PropertyName);
+
+Returns value of I<PropertyName> associated with graph in a I<Graph>.
+
+=item B<GetIncidenceMatrix>
+
+    $GraphMatrix = $Graph->GetIncidenceMatrix();
+
+Returns incidence matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices and e edges, the incidence matrix for G is a n x e matrix
+its elements Mij are:
+
+    . 1    if vertex Vi and the edge Ej are incident; in other words, Vi and Ej are related
+    . 0    otherwise
+
+=item B<GetIsolatedVertices>
+
+    @VertexIDs = $Graph->GetIsolatedVertices();
+
+Returns an array I<VertexIDs> containing vertices without any edges in I<Graph>.
+
+=item B<GetKirchhoffMatrix>
+
+    $GraphMatrix = $Graph->GetGetKirchhoffMatrix();
+
+Returns Kirchhoff matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+B<KirchhoffMatrix> is another name for B<LaplacianMatrix>.
+
+=item B<GetLaplacianMatrix>
+
+    $GraphMatrix = $Graph->GetLaplacianMatrix();
+
+Returns Laplacian matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the Laplacian matrix for G is a n x n square matrix and
+its elements Mij are:
+
+    . deg(Vi)   if i == j and deg(Vi) is the degree of vertex Vi
+    . -1        if i != j and vertex Vi is adjacent to vertex Vj
+    . 0         otherwise
+
+=item B<GetLargestCycle>
+
+    $CyclicPath = $Graph->GetLargestCycle();
+
+Returns a cyclic I<Path> object corresponding to largest cycle in a I<Graph>.
+
+=item B<GetLargestEdgeCycle>
+
+    $CyclicPath = $Graph->GetLargestEdgeCycle($VertexID1, $VertexID2);
+
+Returns a cyclic I<Path> object corresponding to largest cycle containing edge between
+I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetLargestVertexCycle>
+
+    $CyclicPath = $Graph->GetLargestVertexCycle($VertexID);
+
+Returns a cyclic I<Path> object corresponding to largest cycle containing I<VertexID>
+in a I<Graph>.
+
+=item B<GetLeafVertices>
+
+    @VertexIDs = $Graph->GetLeafVertices();
+
+Returns an array I<VertexIDs> containing vertices with degree of 1 in a I<Graph>.
+
+=item B<GetMaximumDegree>
+
+    $Degree = $Graph->GetMaximumDegree();
+
+Returns value of maximum vertex degree in a I<Graph>.
+
+=item B<GetMininumDegree>
+
+    $Degree = $Graph->GetMininumDegree();
+
+Returns value of minimum vertex degree in a I<Graph>.
+
+=item B<GetNeighborhoodVertices>
+
+    @VertexNeighborhoods = GetNeighborhoodVertices($StartVertexID);
+
+Returns an array I<VertexNeighborhoods> containing references to arrays corresponding to
+neighborhood vertices around a specified I<StartVertexID> at all possible radii levels.
+
+=item B<GetNeighborhoodVerticesWithRadiusUpto>
+
+    @VertexNeighborhoods = GetNeighborhoodVerticesWithRadiusUpto(
+                           $StartVertexID, $Radius);
+
+Returns an array I<VertexNeighborhoods> containing references to arrays corresponding to
+neighborhood vertices around a specified I<StartVertexID> upto specified I<Radius> levels.
+
+=item B<GetNeighborhoodVerticesWithSuccessors>
+
+    @VertexNeighborhoods = GetNeighborhoodVerticesWithSuccessors(
+                           $StartVertexID);
+
+Returns vertex neighborhoods around a specified I<StartVertexID>, along with their successor
+connected vertices, collected at all neighborhood radii as an array I<VertexNeighborhoods>
+containing references to arrays with first value corresponding to vertex ID and second
+value as reference to an array  containing its successor connected vertices.
+
+For a neighborhood vertex at each radius level, the successor connected vertices correspond to the
+neighborhood vertices at the next radius level. Consequently, the neighborhood vertices at the last
+radius level don't contain any successor vertices which fall outside the range of specified radius.
+
+=item B<GetNeighborhoodVerticesWithSuccessorsAndRadiusUpto>
+
+    @VertexNeighborhoods = GetNeighborhoodVerticesWithSuccessors(
+                           $StartVertexID, $Radius);
+
+Returns vertex neighborhoods around a specified I<StartVertexID>, along with their successor
+connected vertices, collected with in a specified I<Radius> as an array I<VertexNeighborhoods>
+containing references to arrays with first value corresponding to vertex ID and second value
+as reference to a list containing its successor connected vertices.
+
+For a neighborhood vertex at each radius level, the successor connected vertices correspond to the
+neighborhood vertices at the next radius level. Consequently, the neighborhood vertices at the last
+radius level don't contain any successor vertices which fall outside the range of specified radius.
+
+=item B<GetNeighbors>
+
+    @VertexIDs = $Graph->GetNeighbors($VertexID);
+    $NumOfNeighbors = $Graph->GetNeighbors($VertexID);
+
+Returns an array I<VertexIDs> containing vertices connected to I<VertexID> of number of
+neighbors of a I<VertextID> in a I<Graph>.
+
+=item B<GetNormalizedLaplacianMatrix>
+
+    $GraphMatrix = $Graph->GetNormalizedLaplacianMatrix();
+
+Returns normalized Laplacian matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the normalized Laplacian matrix L for G is a n x n square
+matrix and its elements Lij are:
+
+    .  1                           if i == j and deg(Vi) != 0
+    .  -1/SQRT(deg(Vi) * deg(Vj))  if i != j and vertex Vi is adjacent to vertex Vj
+    .  0                           otherwise
+
+=item B<GetNumOfCycles>
+
+    $NumOfCycles = $Graph->GetNumOfCycles();
+
+Returns number of cycles in a I<Graph>.
+
+=item B<GetNumOfCyclesWithEvenSize>
+
+    $NumOfCycles = $Graph->GetNumOfCyclesWithEvenSize();
+
+Returns number of cycles with even size in a I<Graph>.
+
+=item B<GetNumOfCyclesWithOddSize>
+
+    $NumOfCycles = $Graph->GetNumOfCyclesWithOddSize();
+
+Returns number of cycles with odd size in a I<Graph>.
+
+=item B<GetNumOfCyclesWithSize>
+
+    $NumOfCycles = $Graph->GetNumOfCyclesWithSize($CycleSize);
+
+Returns number of cycles with I<CyclesSize> in a I<Graph>.
+
+=item B<GetNumOfCyclesWithSizeGreaterThan>
+
+    $NumOfCycles = $Graph->GetNumOfCyclesWithSizeGreaterThan(
+                   $CycleSize);
+
+Returns number of cycles with size greater than I<CyclesSize> in a I<Graph>.
+
+=item B<GetNumOfCyclesWithSizeLessThan>
+
+    $NumOfCycles = $Graph->GetNumOfCyclesWithSizeLessThan($CycleSize);
+
+Returns number of cycles with size less than I<CyclesSize> in a I<Graph>.
+
+=item B<GetNumOfEdgeCycles>
+
+    $NumOfCycles = $Graph->GetNumOfEdgeCycles($VertexID1, $VertexID2);
+
+Returns number of cycles containing edge between I<VertexID1> and I<VertexID2>
+in a I<Graph>.
+
+=item B<GetNumOfEdgeCyclesWithEvenSize>
+
+    $NumOfCycles = $Graph->GetNumOfEdgeCyclesWithEvenSize($VertexID1,
+                   $VertexID2);
+
+Returns number of cycles containing edge between I<VertexID1> and I<VertexID2> with even
+size in a I<Graph>.
+
+=item B<GetNumOfEdgeCyclesWithOddSize>
+
+    $NumOfCycles = $Graph->GetNumOfEdgeCyclesWithOddSize($VertexID1,
+                   $VertexID2);
+
+Returns number of cycles containing edge between I<VertexID1> and I<VertexID2> with odd
+size in a I<Graph>.
+
+=item B<GetNumOfEdgeCyclesWithSize>
+
+    $NumOfCycles = $Graph->GetNumOfEdgeCyclesWithSize($VertexID1,
+                   $VertexID2, $CycleSize);
+
+Returns number of cycles containing edge between I<VertexID1> and I<VertexID2> with
+I<CycleSize> size in a I<Graph>.
+
+=item B<GetNumOfEdgeCyclesWithSizeGreaterThan>
+
+    $NumOfCycles = $Graph->GetNumOfEdgeCyclesWithSizeGreaterThan(
+                   $VertexID1, $VertexID2, $CycleSize);
+
+Returns number of cycles containing edge between I<VertexID1> and I<VertexID2> with
+size greater than I<CycleSize> size in a I<Graph>.
+
+=item B<GetNumOfEdgeCyclesWithSizeLessThan>
+
+    $NumOfCycles = $Graph->GetNumOfEdgeCyclesWithSizeLessThan(
+                   $VertexID1, $VertexID2, $CycleSize);
+
+Returns number of cycles containing edge between I<VertexID1> and I<VertexID2> with
+size less than I<CycleSize> size in a I<Graph>.
+
+=item B<GetNumOfVertexCycles>
+
+    $NumOfCycles = $Graph->GetNumOfVertexCycles($VertexID);
+
+Returns number of cycles containing I<VertexID> in a I<Graph>.
+
+=item B<GetNumOfVertexCyclesWithEvenSize>
+
+    $NumOfCycles = $Graph->GetNumOfVertexCyclesWithEvenSize($VertexID);
+
+Returns number of cycles containing I<VertexID> with even size in a I<Graph>.
+
+=item B<GetNumOfVertexCyclesWithOddSize>
+
+    $NumOfCycles = $Graph->GetNumOfVertexCyclesWithOddSize($VertexID);
+
+Returns number of cycles containing I<VertexID> with odd size in a I<Graph>.
+
+=item B<GetNumOfVertexCyclesWithSize>
+
+    $NumOfCycles = $Graph->GetNumOfVertexCyclesWithSize($VertexID);
+
+Returns number of cycles containing I<VertexID> with even size in a I<Graph>.
+
+=item B<GetNumOfVertexCyclesWithSizeGreaterThan>
+
+    $NumOfCycles = $Graph->GetNumOfVertexCyclesWithSizeGreaterThan(
+                   $VertexID, $CycleSize);
+
+Returns number of cycles containing I<VertexID> with size greater than I<CycleSize>
+in a I<Graph>.
+
+=item B<GetNumOfVertexCyclesWithSizeLessThan>
+
+    $NumOfCycles = $Graph->GetNumOfVertexCyclesWithSizeLessThan(
+                   $VertexID, $CycleSize);
+
+Returns number of cycles containing I<VertexID> with size less than I<CycleSize>
+in a I<Graph>.
+
+=item B<GetPaths>
+
+    $PathsRefs = $Graph->GetPaths([$AllowCycles]);
+
+Returns a reference to an array of I<Path> objects corresponding to paths of all possible
+lengths starting from each vertex with no sharing of edges in paths traversed. By default,
+cycles are included in paths. A path containing a cycle is terminated at a vertex completing
+the cycle.
+
+=item B<GetPathsBetween>
+
+    @Paths = $Graph->GetPathsBetween($StartVertexID, $EndVertexID);
+
+Returns an arrays of I<Path> objects list of paths between I<StartVertexID> and I<EndVertexID>.
+For cyclic graphs, the list contains may contain more than one I<Path> object.
+
+=item B<GetPathsStartingAt>
+
+    @Paths = $Graph->GetPathsStartingAt($StartVertexID, [$AllowCycles]);
+
+Returns an array of I<Path> objects corresponding to all possible lengths starting from a
+specified I<StartVertexID> with no sharing of edges in paths traversed. By default, cycles
+are included in paths. A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetPathsStartingAtWithLength>
+
+    @Paths = $Graph->StartingAtWithLength($StartVertexID, $Length,
+             $AllowCycles);
+
+Returns an array of I<Path> objects corresponding to all paths starting from a specified I<StartVertexID>
+with length I<Length> and no sharing of edges in paths traversed. By default, cycles are included in paths.
+A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetPathsStartingAtWithLengthUpto>
+
+    @Paths = $Graph->StartingAtWithLengthUpto($StartVertexID, $Length,
+             $AllowCycles);
+
+Returns an array of I<Path> objects corresponding to all paths starting from a specified I<StartVertexID>
+with length upto I<Length> and no sharing of edges in paths traversed. By default, cycles are included in paths.
+A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetPathsWithLength>
+
+    @Paths = $Graph->GetPathsWithLength($Length, $AllowCycles);
+
+Returns an array of I<Path> objects corresponding to to paths starting from each vertex in graph
+with specified <Length> and no sharing of edges in paths traversed. By default, cycles are included
+in paths. A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetPathsWithLengthUpto>
+
+    @Paths = $Graph->GetPathsWithLengthUpto($Length, $AllowCycles);
+
+Returns an array of I<Path> objects corresponding to to paths starting from each vertex in graph
+with length upto specified I<Length> and no sharing of edges in paths traversed. By default,
+cycles are included in paths. A path containing a cycle is terminated at a vertex completing the cycle.
+
+=item B<GetSiedelAdjacencyMatrix>
+
+    $GraphMatrix = $Graph->GetSiedelAdjacencyMatrix();
+
+Returns Siedel admittance matrix for I<Graph> as a I<GraphMatrix> object with row and column indices
+corresponding to graph vertices returned by GetVertices method.
+
+For a simple graph G with n vertices, the Siedal adjacency matrix for G is a n x n square matrix and
+its elements Mij are:
+
+    . 0    if i == j
+    . -1   if i != j and vertex Vi is adjacent to vertex Vj
+    . 1    if i != j and vertex Vi is not adjacent to vertex Vj
+
+=item B<GetSizeOfLargestCycle>
+
+    $Size = $Graph->GetSizeOfLargestCycle();
+
+Returns size of the largest cycle in a I<Graph>.
+
+=item B<GetSizeOfLargestEdgeCycle>
+
+    $Size = $Graph->GetSizeOfLargestEdgeCycle($VertexID1, $VertexID2);
+
+Returns size of the largest cycle containing egde between I<VertextID1> and  I<VertexID2>
+in a I<Graph>.
+
+=item B<GetSizeOfLargestVertexCycle>
+
+    $Size = $Graph->GetSizeOfLargestVertexCycle($VertexID);
+
+Returns size of the largest cycle containing  I<VertextID> in a I<Graph>.
+
+=item B<GetSizeOfSmallestCycle>
+
+    $Size = $Graph->GetSizeOfSmallestCycle();
+
+Returns size of the smallest cycle in a I<Graph>.
+
+=item B<GetSizeOfSmallestEdgeCycle>
+
+    $Size = $Graph->GetSizeOfSmallestEdgeCycle($VertexID1, $VertexID2);
+
+Returns size of the smallest cycle containing egde between I<VertextID1> and  I<VertexID2>
+in a I<Graph>.
+
+=item B<GetSizeOfSmallestVertexCycle>
+
+    $Size = $Graph->GetSizeOfSmallestVertexCycle($VertexID);
+
+Returns size of the smallest cycle containing  I<VertextID> in a I<Graph>.
+
+=item B<GetSmallestCycle>
+
+    $CyclicPath = $Graph->GetSmallestCycle();
+
+Returns a cyclic I<Path> object corresponding to smallest cycle in a I<Graph>.
+
+=item B<GetSmallestEdgeCycle>
+
+    $CyclicPath = $Graph->GetSmallestEdgeCycle($VertexID1, $VertexID2);
+
+Returns a cyclic I<Path> object corresponding to smallest cycle containing edge between
+I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<GetSmallestVertexCycle>
+
+    $CyclicPath = $Graph->GetSmallestVertexCycle($VertexID);
+
+Returns a cyclic I<Path> object corresponding to smallest cycle containing I<VertexID> in a I<Graph>.
+
+=item B<GetTopologicallySortedVertices>
+
+    @VertexIDs = $Graph->GetTopologicallySortedVertices(
+                 [$RootVertexID]);
+
+Returns an array of I<VertexIDs> sorted topologically starting from a specified I<RootVertexID> or
+from an arbitrary vertex ID.
+
+=item B<GetVertex>
+
+    $VertexValue = $Graph->GetVertex($VertexID);
+
+Returns vartex value for I<VertexID> in a I<Graph>. Vartex IDs and values are equivalent
+in the current implementation of B<Graph>.
+
+=item B<GetVertexCycles>
+
+    @CyclicPaths = $Graph->GetVertexCycles($VertexID);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to all cycles containing
+I<VertexID> in a I<Graph>.
+
+=item B<GetVertexCyclesWithEvenSize>
+
+    @CyclicPaths = $Graph->GetVertexCyclesWithEvenSize($VertexID);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+even size containing I<VertexID> in a I<Graph>.
+
+=item B<GetVertexCyclesWithOddSize>
+
+    @CyclicPaths = $Graph->GetVertexCyclesWithOddSize($VertexID);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+odd size containing I<VertexID> in a I<Graph>.
+
+=item B<GetVertexCyclesWithSize>
+
+    @CyclicPaths = $Graph->GetVertexCyclesWithSize($VertexID,
+                   $CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size I<CycleSize> containing I<VertexID> in a I<Graph>.
+
+=item B<GetVertexCyclesWithSizeGreaterThan>
+
+    @CyclicPaths = $Graph->GetVertexCyclesWithSizeGreaterThan($VertexID,
+                   $CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size greater than I<CycleSize> containing I<VertexID> in a I<Graph>.
+
+=item B<GetVertexCyclesWithSizeLessThan>
+
+    @CyclicPaths = $Graph->GetVertexCyclesWithSizeLessThan($VertexID,
+                   $CycleSize);
+
+Returns an array I<CyclicPaths> containing I<Path> objects corresponding to cycles with
+size less than I<CycleSize> containing I<VertexID> in a I<Graph>.
+
+=item B<GetVertexProperties>
+
+    %VertexProperties = $Graph->GetVertexProperties($VertexID);
+
+Returns a hash B<VertexProperties> containing all B<PropertyName> and B<PropertyValue>
+pairs associated with a I<VertexID> in a I<Graph>.
+
+=item B<GetVertexProperty>
+
+    $Value = $Graph->GetVertexProperty($PropertyName, $VertexID);
+
+Returns value of I<PropertyName> associated with a I<VertexID> in a I<Graph>.
+
+=item B<GetVertexWithLargestDegree>
+
+    $VertexID = $Graph->GetVertexWithLargestDegree();
+
+Returns B<VertexID> with largest degree in a I<Graph>.
+
+=item B<GetVertexWithSmallestDegree>
+
+    $VertexID = $Graph->GetVertexWithSmallestDegree();
+
+Returns B<VertexID> with smallest degree in a I<Graph>.
+
+=item B<GetVertices>
+
+    @VertexIDs = $Graph->GetVertices();
+    $VertexCount = $Graph->GetVertices();
+
+Returns an array of I<VertexIDs> corresponding to all vertices in a I<Graph>; in a scalar context,
+number of vertices is returned.
+
+=item B<GetVerticesProperty>
+
+    @PropertyValues = $Graph->GetVerticesProperty($PropertyName, @VertexIDs);
+
+Returns an array I<PropertyValues> containing property values corresponding to
+I<PropertyName> associated with with I<VertexIDs> in a I<Graph>.
+
+=item B<GetVerticesWithDegreeLessThan>
+
+    @VertexIDs  = $Graph->GetVerticesWithDegreeLessThan($Degree);
+
+Returns an array of I<VertexIDs> containing vertices with degree less than I<Degree> in
+a I<Graph>.
+
+=item B<HasCycle>
+
+    $Status = $Graph->HasCycle(@VertexIDs);
+
+Returns 1 or 0 based on whether edges between successive pair of I<VertexIDs> including
+an additional edge from the last to first vertex ID exists in a I<Graph>.
+
+=item B<HasEdge>
+
+    $Status = $Graph->HasEdge($VertexID1, $VertexID2);
+
+Returns 1 or 0 based on whether an edge between I<VertexID1> and I<VertexID2> exist in
+a I<Graph>.
+
+=item B<HasEdgeProperty>
+
+    $Status = $Graph->HasEdgeProperty($PropertyName, $VertexID1,
+              $VertexID2);
+
+Returns 1 or 0 based on whether I<PropertyName> has already been associated with an edge
+between I<VertexID1> and I<VertexID2> in a I<Graph>.
+
+=item B<HasEdges>
+
+    @EdgesStatus = $Graph->HasEdges(@VertexIDs);
+    $FoundEdgesCount = $Graph->HasEdges(@VertexIDs);
+
+Returns an array I<EdgesStatus> containing 1s and 0s corresponding to whether edges between
+successive pairs of I<VertexIDs> exist in a I<Graph>. In a scalar context, number of edges found
+is returned.
+
+=item B<HasFusedCycles>
+
+    $Status = $Graph->HasFusedCycles();
+
+Returns 1 or 0 based on whether any fused cycles exist in a I<Graph>.
+
+=item B<HasGraphProperty>
+
+    $Status = $Graph->HasGraphProperty($PropertyName);
+
+Returns 1 or 0 based on whether I<PropertyName> has already been associated as a
+graph property as opposed to vertex or edge property in a I<Graph>.
+
+=item B<HasPath>
+
+    $Status = $Graph->HasPath(@VertexIDs));
+
+Returns 1 or 0 based on whether edges between all successive pairs of I<VertexIDs> exist in
+a I<Graph>.
+
+=item B<HasVertex>
+
+    $Status = $Graph->HasVertex($VertexID);
+
+Returns 1 or 0 based on whether I<VertexID> exists in a I<Graph>.
+
+=item B<HasVertexProperty>
+
+    $Status = $Graph->HasGraphProperty($HasVertexProperty, $VertexID);
+
+Returns 1 or 0 based on whether I<PropertyName> has already been associated with
+I<VertexID> in a I<Graph>.
+
+=item B<HasVertices>
+
+    @VerticesStatus = $Graph->HasVertices(@VertexIDs);
+    $VerticesFoundCount = $Graph->HasVertices(@VertexIDs);
+
+Returns an array I<> containing 1s and 0s corresponding to whether I<VertexIDs> exist in a 
+I<Graph>. In a scalar context, number of vertices found is returned.
+
+=item B<IsAcyclic>
+
+    $Status = $Graph->IsAcyclic();
+
+Returns 0 or 1 based on whether a cycle exist in a I<Graph>.
+
+=item B<IsAcyclicEdge>
+
+    $Status = $Graph->IsAcyclicEdge($VertexID1, $VertexID2);
+
+Returns 0 or 1 based on whether a cycle containing an edge between I<VertexID1> and
+I<VertexID2> exists in a I<Graph>.
+
+=item B<IsAcyclicVertex>
+
+    $Status = $Graph->IsAcyclicVertex($VertexID1);
+
+Returns 0 or 1 based on whether a cycle containing a I<VertexID> exists in a I<Graph>.
+
+=item B<IsCyclic>
+
+    $Status = $Graph->IsCyclic();
+
+Returns 1 or 0 based on whether a cycle exist in a I<Graph>.
+
+=item B<IsCyclicEdge>
+
+    $Status = $Graph->IsCyclicEdge($VertexID1, $VertexID2);
+
+Returns 1 or 0 based on whether a cycle containing an edge between I<VertexID1> and
+I<VertexID2> exists in a I<Graph>.
+
+=item B<IsCyclicVertex>
+
+    $Status = $Graph->IsCyclicVertex($VertexID1);
+
+Returns 1 or 0 based on whether a cycle containing a I<VertexID> exists in a I<Graph>.
+
+=item B<IsGraph>
+
+    $Status = Graph::IsGraph($Object);
+
+Returns 1 or 0 based on whether I<Object> is a B<Graph> object.
+
+=item B<IsIsolatedVertex>
+
+    $Status = $Graph->IsIsolatedVertex($VertexID);
+
+Returns 1 or 0 based on whether I<VertexID> is an isolated vertex in a I<Graph>. A vertex
+with zero as its degree value is considered an isolated vertex.
+
+=item B<IsLeafVertex>
+
+    $Status = $Graph->IsLeafVertex($VertexID);
+
+Returns 1 or 0 based on whether I<VertexID> is an isolated vertex in a I<Graph>. A vertex
+with one as its degree value is considered an isolated vertex.
+
+=item B<IsUnicyclic>
+
+    $Status = $Graph->IsUnicyclic();
+
+Returns 1 or 0 based on whether only one cycle is present in a I<Graph>.
+
+=item B<IsUnicyclicEdge>
+
+    $Status = $Graph->IsUnicyclicEdge($VertexID1, $VertexID2);
+
+Returns 1 or 0 based on whether only one cycle contains the edge between I<VertexID1> and
+I<VertexID2> in a I<Graph>.
+
+=item B<IsUnicyclicVertex>
+
+    $Status = $Graph->IsUnicyclicVertex($VertexID);
+
+Returns 1 or 0 based on whether only one cycle contains I<VertexID> in a I<Graph>.
+
+=item B<SetActiveCyclicPaths>
+
+    $Graph->SetActiveCyclicPaths($CyclicPathsType);
+
+Sets the type of cyclic paths to use during all methods related to cycles and returns I<Graph>.
+Possible values for cyclic paths: I<Independent or All>.
+
+=item B<SetEdgeProperties>
+
+    $Graph->SetEdgeProperties($VertexID1, $VertexID2, @NamesAndValues);
+
+Associates property names and values corresponding to successive pairs of values in
+I<NamesAndValues> to an edge between I<VertexID1> and I<VertexID2> in a I<Graph>
+and returns I<Graph>.
+
+=item B<SetEdgeProperty>
+
+    $Graph->SetEdgeProperty($Name, $Value, $VertexID1, $VertexID2);
+
+Associates property I<Name> and I<Value> to an edge between I<VertexID1> and I<VertexID2>
+in a I<Graph> and returns I<Graph>.
+
+=item B<SetEdgesProperty>
+
+    $Graph->SetEdgesProperty($Name, @ValuesAndVertexIDs);
+
+Associates a same property I<Name> but different I<Values> for different edges specified using
+triplets of I<PropertyValue, $VertexID1, $VertexID2> via I<ValuesAndVertexIDs> in a I<graph>.
+
+=item B<SetGraphProperties>
+
+    $Graph->SetGraphProperties(%NamesAndValues);
+
+Associates property names and values I<NamesAndValues> hash to graph as opposed to vertex
+or edge and returns I<Graph>.
+
+=item B<SetGraphProperty>
+
+    $Graph->SetGraphProperty($Name, $Value);
+
+Associates property I<Name> and I<Value> to graph as opposed to vertex
+or edge and returns I<Graph>.
+
+=item B<SetVertexProperties>
+
+    $Graph->SetVertexProperties($VertexID, @NamesAndValues);
+
+Associates property names and values corresponding to successive pairs of values in
+I<NamesAndValues> to I<VertexID> in a I<Graph> and returns I<Graph>.
+
+=item B<SetVertexProperty>
+
+    $Graph->SetVertexProperty($Name, $Value, $VertexID);
+
+Associates property I<Name> and I<Value> to I<VertexID> in a I<Graph> and returns I<Graph>.
+
+=item B<SetVerticesProperty>
+
+    $Graph->SetVerticesProperty($Name, @ValuesAndVertexIDs));
+
+Associates a same property I<Name> but different I<Values> for different vertices specified using
+doublets of I<PropertyValue, $VertexID> via I<ValuesAndVertexIDs> in a I<graph>.
+
+=item B<StringifyEdgesProperties>
+
+    $String = $Graph->StringifyEdgesProperties();
+
+Returns a string containing information about properties associated with all edges in a I<Graph> object.
+
+=item B<StringifyGraph>
+
+    $String = $Graph->StringifyGraph();
+
+Returns a string containing information about I<Graph> object.
+
+=item B<StringifyGraphProperties>
+
+    $String = $Graph->StringifyGraphProperties();
+
+Returns a string containing information about properties associated with graph as opposed to vertex.
+or an edge in a I<Graph> object
+
+=item B<StringifyProperties>
+
+    $String = $Graph->StringifyProperties();
+
+Returns a string containing information about properties associated with graph, vertices, and edges in
+a I<Graph> object.
+
+=item B<StringifyVerticesAndEdges>
+
+    $String = $Graph->StringifyVerticesAndEdges();
+
+Returns a string containing information about vertices and edges in a I<Graph> object.
+
+=item B<StringifyVerticesProperties>
+
+    $String = $Graph->StringifyVerticesProperties();
+
+Returns a string containing information about properties associated with vertices a I<Graph> object.
+
+=item B<UpdateEdgeProperty>
+
+    $Graph->UpdateEdgeProperty($Name, $Value, $VertexID1, $VertexID2);
+
+Updates property I<Value> for I<Name> associated with an edge between I<VertexID1> and
+I<VertexID1> and returns I<Graph>.
+
+=item B<UpdateVertexProperty>
+
+    $Graph->UpdateVertexProperty($Name, $Value, $VertexID);
+
+Updates property I<Value> for I<Name> associated with I<VertexID> and returns I<Graph>.
+
+=back
+
+=head1 AUTHOR
+
+Manish Sud <msud@san.rr.com>
+
+=head1 SEE ALSO
+
+CyclesDetection.pm, Path.pm, PathGraph.pm, PathsTraversal.pm
+
+=head1 COPYRIGHT
+
+Copyright (C) 2015 Manish Sud. All rights reserved.
+
+This file is part of MayaChemTools.
+
+MayaChemTools is free software; you can redistribute it and/or modify it under
+the terms of the GNU Lesser General Public License as published by the Free
+Software Foundation; either version 3 of the License, or (at your option)
+any later version.
+
+=cut
author	deepakjadmin
date	Wed, 20 Jan 2016 11:55:01 -0500
parents
children