anchor.diff:     * descriptors for Dart sources.
      */
     @ExtensionPointId('DART_ERRORS_FOR_SOURCE_EXTENSION_POINT_ID')
  -  List<TaskDescriptor> get dartErrorsForSource =>
  +  List<ResultDescriptor> get dartErrorsForSource =>
         dartErrorsForSourceExtensionPoint.extensions;
   
     /**
  
positive.code:    * descriptors for Dart library specific units.
     */
    @ExtensionPointId('DART_ERRORS_FOR_UNIT_EXTENSION_POINT_ID')
    List<TaskDescriptor> get dartErrorsForUnit =>
        dartErrorsForUnitExtensionPoint.extensions;
  
    /**
  
negative.code:    * descriptors for HTML sources.
     */
    @ExtensionPointId('HTML_ERRORS_EXTENSION_POINT_ID')
    List<ResultDescriptor> get htmlErrors => htmlErrorsExtensionPoint.extensions;
  
    /**
     * Return a list containing all of the task descriptors that were contributed.
  