Public Class DemoTestClass
    Dim _testcollection As New TestClassCollection
 
    Public Sub InitCollection()
        _testcollection.Add(New TestClass)
        _testcollection.Add(New TestClass)
        _testcollection.Add(New TestClass)
    End Sub
 
    Public Sub Run()
        For Each tclass As TestClass In _testcollection
            tclass.DoSomething()
        Next
    End Sub
End Class

Public Class TestClass
 
    Public Sub DoSomething()
 
    End Sub
 
End Class

Public Class TestClassCollection
    Implements IList(Of TestClass)
 
    Private _classlist As List(Of TestClass)
 
    Public Sub New()
        _classlist = New List(Of TestClass)
    End Sub
 
    Public Sub Add(ByVal item As TestClass) Implements _
      System.Collections.Generic.ICollection(Of TestClass).Add
        _classlist.Add(item)
    End Sub
 
    ' ....
 
End Class