public void Handle_D_BlockMode()
 {
     Create("dog", "cat", "tree");
     EnterBlock(_textView.GetBlock(1, 1, 0, 2));
     _buffer.Process("D");
     Assert.AreEqual("d", _textView.GetLine(0).GetText());
     Assert.AreEqual("c", _textView.GetLine(1).GetText());
 }