The Dark Shadow of Overrides

Module Module1

    Sub Main()
        Dim A As Invoice = New TimeMaterialsInvoice1()
        Console.WriteLine("Dim A As Invoice = New TimeMaterialsInvoice1()")
        A.ProcessInvoice()
        Dim B As Invoice = New TimeMaterialsInvoice2()
        Console.WriteLine("Dim B As Invoice = New TimeMaterialsInvoice2()")
        B.ProcessInvoice()
        Dim C As Invoice = New TimeMaterialsInvoice3()
        Console.WriteLine("Dim C As Invoice = New TimeMaterialsInvoice3()")
        C.ProcessInvoice()

        Console.WriteLine()
        Console.WriteLine()

        Dim D As InvoiceAlt = New TimeMaterialsInvoiceAlt1()
        Console.WriteLine("Dim D As InvoiceAlt = New TimeMaterialsInvoiceAlt1()")
        D.ProcessInvoice()
        Dim E As InvoiceAlt = New TimeMaterialsInvoiceAlt2()
        Console.WriteLine("Dim E As InvoiceAlt = New TimeMaterialsInvoiceAlt2()")
        E.ProcessInvoice()
        Dim F As InvoiceAlt = New TimeMaterialsInvoiceAlt3()
        Console.WriteLine("Dim F As InvoiceAlt = New TimeMaterialsInvoiceAlt3()")
        F.ProcessInvoice()

        Console.WriteLine()
        Console.WriteLine()

        Dim G As InvoiceStk = New TimeMaterialsInvoiceStk()
        Console.WriteLine("Dim G As InvoiceStk = New TimeMaterialsInvoiceStk()")
        G.ProcessInvoice()
        Dim H As InvoiceStk = New TimeMaterialsInvoiceStk2()
        Console.WriteLine("Dim H As InvoiceStk = New TimeMaterialsInvoiceStk2()")
        H.ProcessInvoice()

        Console.ReadLine()

    End Sub

End Module