public void setUp()
 {
     this.document = new TextEditorDocument("example.txt");
     this.initialDocument = new TextEditorDocument("example.txt");
     this.document.Lines.Add("hello");
     this.document.Lines.Add("world");
     this.document.Lines.Add("");
     this.document.Lines.Add("123");
     this.document.Lines.ForEach(l => this.initialDocument.Lines.Add(l));
 }
 /// <summary>
 /// Initializes a new instance of the <see cref="TextEditorDocumentProxy"/> class.
 /// </summary>
 /// <param name="document">Real document.</param>
 public TextEditorDocumentProxy(TextEditorDocument document)
 {
     this.document = document;
 }