anchor.diff:            resolvedUnits.add(
               new AnalysisResult(
                 currentSession,
  -              _sourceFactory,
                 unitFile.path,
                 unitFile.uri,
                 unitFile.exists,
  
positive.code:       this._index)
        : super(session, path, uri, exists, content, lineInfo, isPart, unit,
              errors);
  
    @override
    LibraryElement get libraryElement => unit.declaredElement.library;
  
    @override
    TypeProvider get typeProvider => libraryElement.typeProvider;
  
    @override
    TypeSystemImpl get typeSystem => libraryElement.typeSystem;
  }
  
  class DriverPerformance {
  
negative.code:     _updateHasErrorOrWarningFlag(file, errors);
      return new AnalysisResult(
          currentSession,
          file.path,
          file.uri,
          file.exists,
  