anchor.diff:          _processElement(stackTraceElement);
         }
       }
  -    return super.visitCatchClause(node);
  -  }
  -
  -  @override
  -  Object visitClassDeclaration(ClassDeclaration node) {
  +    super.visitCatchClause(node);
  +  }
  +
  +  @override
  +  visitClassDeclaration(ClassDeclaration node) {
       String name = node.name.name;
       ClassElement clazz = _findElement(_enclosingUnit.types, name);
       _enclosingClass = clazz;
  
positive.code:     try {
        _enclosingParameter = element;
        _processElement(_enclosingParameter);
        return super.visitDefaultFormalParameter(node);
      } finally {
        _enclosingParameter = outerParameter;
      }
    }
  
    @override
    Object visitEnumDeclaration(EnumDeclaration node) {
      ClassElement enclosingEnum =
          _findIdentifier(_enclosingUnit.enums, node.name);
      _processElement(enclosingEnum);
  
negative.code:             _enclosingClass.getNamedConstructor(constructorName.name);
        }
        _processElement(_enclosingExecutable);
        super.visitConstructorDeclaration(node);
      } finally {
        _enclosingExecutable = outerExecutable;
      }
    }
  
    @override
    visitDeclaredIdentifier(DeclaredIdentifier node) {
      SimpleIdentifier variableName = node.identifier;
      LocalVariableElement element =
          _findIdentifier(_enclosingExecutable.localVariables, variableName);
      _processElement(element);
      super.visitDeclaredIdentifier(node);
    }
  
    @override
    visitDefaultFormalParameter(DefaultFormalParameter node) {
      SimpleIdentifier parameterName = node.parameter.identifier;
      ParameterElement element = _getElementForParameter(node, parameterName);
      Expression defaultValue = node.defaultValue;
  