private void SetCurrent()
        {
            var codeLines = _te.Document.GetCodeLines();
            var codeText  = codeLines.SelectMany(l => _te.Document.GetText(l).TrimStart('>') + Environment.NewLine);

            codeText = codeText.Take(codeText.Count() - Environment.NewLine.Length); //Remove last line break
            var text = new string(codeText.ToArray());

            _newText = new InteractiveText(text);
        }
 private void DocumentOnChanging(object sender, DocumentChangeEventArgs e)
 {
     _oldText = (InteractiveText)CurrentText;
 }