anchor.diff:      // notification (in fileContentsChanged()), we compare the last write to the
       // contents on disk.
       if (_dirty) {
  -      // Remove the trailing whitespace if asked to do so
  +      // Remove the trailing whitespace if asked to do so.
         // TODO(ericarnold): Can't think of an easy way to share this preference,
         //           but it might be a good idea to do so rather than passing it.
         if (stripWhitespace) _stripWhitespace();
  
positive.code:     }
    }
  
    _stripWhitespace() {
      html.Point cursorPosition = aceManager.cursorPosition;
      RegExp whitespaceRegEx = new RegExp('[\t ]*\$', multiLine:true);
      _session.value = _session.value.replaceAll(whitespaceRegEx, '');
      aceManager.cursorPosition = cursorPosition;
    }
  
    /**
  
negative.code: export 'package:ace/ace.dart' show EditSession;
  
  class TextEditor extends Editor {
    static final RegExp whitespaceRegEx = new RegExp('[\t ]*\$', multiLine:true);
  
    final AceManager aceManager;
    final workspace.File file;
  
  