Private Function CopyList(Of T As Structure) _
     (ByVal arg As List(Of T)) As List(Of T)
     If arg Is Nothing Then Return Nothing
     Dim cl As New List(Of T)
     For i As Integer = 0 To arg.Count - 1
            Dim el As T = arg(i)
            cl.Add(el)
     Next i
     Return cl
End Function