anchor.diff:      classElement.fields = <FieldElement>[fieldElement];
       classDeclaration.name.staticElement = classElement;
       if (hasConstConstructor) {
  -      ConstructorDeclaration constructorDeclaration = AstFactory
  -          .constructorDeclaration2(
  +      ConstructorDeclaration constructorDeclaration =
  +          AstFactory.constructorDeclaration2(
                 Keyword.CONST,
                 null,
                 AstFactory.identifier3(className),
  
positive.code:     GatheringErrorListener errorListener = new GatheringErrorListener();
      ErrorReporter errorReporter =
          new ErrorReporter(errorListener, _dummySource());
      _assertValue(
          0,
          expression.accept(new ConstantVisitor(
              new ConstantEvaluationEngine(
                  new TestTypeProvider(), new DeclaredVariables(),
                  typeSystem: new TypeSystemImpl()),
              errorReporter)));
      errorListener.assertNoErrors();
    }
  
  
negative.code:     _assertIntField(fields, "x", 42);
    }
  
    void
        test_instanceCreationExpression_fieldFormalParameter_namedOptionalWithDefault() {
      _checkInstanceCreationOptionalParams(true, true, true);
    }
  
    void
        test_instanceCreationExpression_fieldFormalParameter_namedOptionalWithoutDefault() {
      _checkInstanceCreationOptionalParams(true, true, false);
    }
  
    void
        test_instanceCreationExpression_fieldFormalParameter_unnamedOptionalWithDefault() {
      _checkInstanceCreationOptionalParams(true, false, true);
    }
  
    void
        test_instanceCreationExpression_fieldFormalParameter_unnamedOptionalWithoutDefault() {
      _checkInstanceCreationOptionalParams(true, false, false);
    }
  
  