Adjacency list representation of directed graph in vb.net

Vb program for Adjacency list representation of directed graph. Here problem description and explanation.

' Include namespace system
Imports System 
'    Vb.net Program for 
'    Directed graph representation using adjacency list
Public Class AjlistNode 
    '  Vertices node key
    Public  id As Integer
    Public  [next] As AjlistNode
    
    Public Sub New(ByVal id As Integer)
        '  Set value of node key
        Me.id = id
        Me.next = Nothing
    
    End Sub

End Class
Public Class Vertices 
    Public  data As Integer
    Public  [next] As AjlistNode
    Public  last As AjlistNode
    Public Sub New(ByVal data As Integer)
        
        Me.data = data
        Me.next = Nothing
        Me.last = Nothing
    
    End Sub

End Class
public Class Graph 
    '  Number of Vertices
    Public  size As Integer
    Public  node As Vertices()
    
    Public Sub New(ByVal size As Integer)
        '  Set value
        Me.size = size
        Me.node = New Vertices(size){}
        Me.setData()
    
    End Sub
    '  Set initial node value
    
    Public Sub setData()
        if (Me.size <= 0) Then 
            Console.WriteLine(vbLf & "Empty Graph")
        Else 
            Dim index As Integer = 0
            While index < Me.size
                ' Set initial node value
                Me.node(index) = New Vertices(index)
            index+=1
            End While
        End IF

    
    End Sub
    '  Connect two nodes
    
    Public Sub connect(ByVal start As Integer, ByVal last As Integer)
        Dim edge As AjlistNode = New AjlistNode(last)
        if (Me.node(start).[next]  Is  Nothing) Then 
            Me.node(start).[next] = edge
        Else 
            '  Add edge at the end
            Me.node(start).last.[next] = edge
        End IF

        '  Get last edge 
        Me.node(start).last = edge
    
    End Sub
    '   Handling the request of adding new edge
    
    Public Sub addEdge(ByVal start As Integer, ByVal last As Integer)
        if (start >= 0 AndAlso start < Me.size AndAlso 
            last >= 0 AndAlso last < Me.size) Then 
            '  Safe connection
            Me.connect(start, last)
        Else 
            '  When invalid nodes
            Console.WriteLine(vbLf & "Here Something Wrong")
        End IF

    
    End Sub
    
    Public Sub printGraph()
        if (Me.size > 0) Then 
            '  Print graph ajlist Node value
            Dim index As Integer = 0
            While index < Me.size

                Console.Write( vbLf &"Adjacency list of vertex " +
                              index.ToString() + " :")
                Dim temp As AjlistNode = Me.node(index).[next]
                
                while (temp IsNot Nothing) 
                    '  Display graph node 
                    Console.Write("  " + Me.node(temp.id).data.ToString())
                    '  visit to next edge
                    temp = temp.[next]
                End While
            index+=1
            End While
        End If

    
    End Sub
    
    Public Shared Sub Main(ByVal args As String())
        '  5 implies the number of nodes in graph
        Dim g As Graph = New Graph(5)
        '  Connect node with an edge
        g.addEdge(0, 1)
        g.addEdge(1, 2)
        g.addEdge(1, 4)
        g.addEdge(2, 0)
        g.addEdge(2, 3)
        g.addEdge(4, 3)
        '  print graph element
        g.printGraph()
    
    End Sub

End Class

Output

Adjacency list of vertex 0 :  1
Adjacency list of vertex 1 :  2  4
Adjacency list of vertex 2 :  0  3
Adjacency list of vertex 3 :
Adjacency list of vertex 4 :  3