Private Sub AddUndoRedoItem(ByVal command As UndoRedoCommand, ByVal [event] As UndoRedoTextBoxEvent,
                                ByVal data As Object, ByVal lastData As Object)

        Console.WriteLine()
        Console.WriteLine("command:" & command.ToString)
        Console.WriteLine("last command:" & lastCommand.ToString)
        Console.WriteLine("can undo:" & Me.CanUndo)
        Console.WriteLine("can redo:" & Me.CanRedo)
        Console.WriteLine("is undoing:" & Me.isUndoingB)
        Console.WriteLine("is redoing:" & Me.isRedoingB)
        Console.WriteLine("data:" & data.ToString)
        Console.WriteLine("last data:" & lastData.ToString)

        ' MsgBox(command.ToString)
        Dim undoRedoData As Object = Nothing
        Me.lastCommand = command

        Select Case command

            Case UndoRedoCommand.Undo

                ' If (Me.lastCommand = UndoRedoCommand.Redo) Then
                '  MsgBox("")
                '  End If

                If (Me.isUndoingB) Then
                    Exit Select
                End If

                If (Me.CanRedo) AndAlso (Me.IsRedoing) Then

                    '  Exit Select
                End If



                'If (Me.CanUndo) AndAlso (Me.CanRedo) AndAlso Not (Me.IsRedoing) Then

                '    Dim redoItem As KeyValuePair(Of UndoRedoTextBoxEvent, Object) = Me.redoStack.Peek

                '    If (redoItem.Key = [event]) AndAlso (Me.undoStack.Peek.Value.Equals(lastData)) Then
                '        MsgBox("undo1")
                '        Me.redoStack.Clear()
                '        Exit Sub
                '    End If

                'End If

                'Select Case (Me.CanRedo)
                '    Case True
                '        If (Me.redoStack.Peek.Key = [event]) Then

                '            If (Me.CanUndo) AndAlso (Me.redoStack.Peek.Value.Equals(Me.undoStack.Peek.Value)) Then
                '                Me.undoStack.Clear()
                '                undoRedoData = Me.redoStack.Peek.Value

                '            Else
                '                undoRedoData = lastData

                '            End If

                '        End If

                '    Case Else
                ' MsgBox("")
                undoRedoData = lastData

                'End Select

                Me.undoStack.Push(New KeyValuePair(Of UndoRedoTextBoxEvent, Object)([event], undoRedoData))

            Case UndoRedoCommand.Redo

                If (Me.isRedoingB) Then
                    Exit Select
                End If


                If (Me.CanRedo) AndAlso (Me.CanUndo) AndAlso (Me.IsUndoing) Then

                    Dim undoItem As KeyValuePair(Of UndoRedoTextBoxEvent, Object) = Me.undoStack.Peek

                    If (undoItem.Key = [event]) AndAlso (undoItem.Value.Equals(lastData)) Then
                        ' MsgBox("h")
                        'Me.undoStack.Push(New KeyValuePair(Of UndoRedoTextBoxEvent, Object)([event], undoItem.Value))
                        ' Me.redoStack.Clear()
                        'Exit Sub
                    End If
                End If



                'If (Me.CanRedo) AndAlso (Me.CanUndo) AndAlso Not (Me.IsUndoing) Then

                '    Dim undoItem As KeyValuePair(Of UndoRedoTextBoxEvent, Object) = Me.undoStack.Peek

                '    If (undoItem.Key = [event]) AndAlso Not (undoItem.Value.Equals(data)) Then
                '        Me.undoStack.Push(New KeyValuePair(Of UndoRedoTextBoxEvent, Object)([event], undoItem.Value))
                '        Me.redoStack.Clear()
                '        Exit Sub
                '    End If

                'End If

                'Select Case (Me.CanUndo)

                '    Case True

                '        If (Me.undoStack.Peek.Key = [event]) Then

                '            If (Me.CanRedo) AndAlso Not (Me.undoStack.Peek.Value.Equals(data)) Then
                '                undoRedoData = data

                '            Else
                '                Me.redoStack.Clear()
                '                undoRedoData = data

                '            End If

                '        End If

                '    Case Else
                undoRedoData = lastData

                'End Select

                Me.redoStack.Push(New KeyValuePair(Of UndoRedoTextBoxEvent, Object)([event], undoRedoData))

        End Select

    End Sub