...
Implements CirculiSDK.PC.Circuli.ICommunication
Public Function ReceiveMessage(ByVal sender As CirculiSDK.PC.Circuli.IPlugIn, _
  ByVal message As CirculiSDK.PC.Circuli.IPlugIn.Messages) As Object Implements _
  CirculiSDK.PC.Circuli.ICommunication.ReceiveMessage
        MsgBox("Ich Circuli")
    End Function
...
plugin.GetMessage(Me, CirculiSDK.PC.Circuli.IPlugIn.Messages.MyMenuItemClick)

    Public Interface IPlugIn
.....
        ReadOnly Property Prop(ByVal Message As _
          CirculiSDK.PC.Circuli.IPlugIn.Messages) As PlugInProperties
        Function GetMessage(ByVal CopyOfMainWindow As Form, ByVal Message As _
        CirculiSDK.PC.Circuli.IPlugIn.Messages) As ReturnProperties
        Property Test() As Circuli.ICommunication
 
    End Interface
 
    Public Interface ICommunication
        Function ReceiveMessage(ByVal sender As CirculiSDK.PC.Circuli.IPlugIn, _
          ByVal message As CirculiSDK.PC.Circuli.IPlugIn.Messages)
    End Interface

Public Class Close
 
    Implements CirculiSDK.PC.Circuli.IPlugIn
 
 
    Public Function GetMessage(ByVal CopyOfMainWindow As _
      System.Windows.Forms.Form, ByVal Message As _
      CirculiSDK.PC.Circuli.IPlugIn.Messages) As _
      CirculiSDK.PC.Circuli.IPlugIn.ReturnProperties Implements _
      CirculiSDK.PC.Circuli.IPlugIn.GetMessage
        If Message = CirculiSDK.PC.Circuli.IPlugIn.Messages.MyMenuItemClick Then
            Test.ReceiveMessage(Nothing, _
              CirculiSDK.PC.Circuli.IPlugIn.Messages.MyMenuItemClick)
        End If
    End Function
 
    Public ReadOnly Property Prop(ByVal Message As _
      CirculiSDK.PC.Circuli.IPlugIn.Messages) As _
      CirculiSDK.PC.Circuli.IPlugIn.PlugInProperties Implements _
      CirculiSDK.PC.Circuli.IPlugIn.Prop
        Get
......
        End Get
    End Property
 
    Public Property Test() As CirculiSDK.PC.Circuli.ICommunication Implements _
      CirculiSDK.PC.Circuli.IPlugIn.Test
        Get
            MsgBox("Get from Property Test")
        End Get
        Set(ByVal Value As CirculiSDK.PC.Circuli.ICommunication)
 
        End Set
    End Property
 
End Class