anchor.diff:      resolve(source);
       assertNoErrors(source);
       verify([source]);
  -    CompilationUnit unit = analysisContext.parseCompilationUnit(source);
  +    CompilationUnit unit = _getResolvedLibraryUnit(source);
       SimpleIdentifier ref = EngineTestCase.findNode(
           unit, code, "p]", (node) => node is SimpleIdentifier);
       EngineTestCase.assertInstanceOf(
  
positive.code:     resolve(source);
      assertNoErrors(source);
      verify([source]);
      CompilationUnit unit = analysisContext.parseCompilationUnit(source);
      {
        SimpleIdentifier ref = EngineTestCase.findNode(
            unit, code, "p1]", (node) => node is SimpleIdentifier);
  
negative.code:   void _check_wrongNumberOfParametersForOperator1(String name) {
      _check_wrongNumberOfParametersForOperator(name, "a");
    }
  
    CompilationUnit _getResolvedLibraryUnit(Source source) =>
        analysisContext.getResolvedCompilationUnit2(source, source);
  }
  