anchor.diff:    InterfaceTypeImpl._(Element element, String name, this.prunedTypedefs)
         : super(element, name);
   
  +
     @override
     List<PropertyAccessorElement> get accessors {
  -    List<PropertyAccessorElement> accessors = element.accessors;
  -    List<PropertyAccessorElement> members =
  -        new List<PropertyAccessorElement>(accessors.length);
  -    for (int i = 0; i < accessors.length; i++) {
  -      members[i] = PropertyAccessorMember.from(accessors[i], this);
  -    }
  -    return members;
  -  }
  +    if (_accessors == null) {
  +      List<PropertyAccessorElement> accessors = element.accessors;
  +      List<PropertyAccessorElement> members =
  +      new List<PropertyAccessorElement>(accessors.length);
  +      for (int i = 0; i < accessors.length; i++) {
  +        members[i] = PropertyAccessorMember.from(accessors[i], this);
  +      }
  +      _accessors = members;
  +    }
  +    return _accessors;
  +  }
  +
   
     @override
     List<ConstructorElement> get constructors {
  -    List<ConstructorElement> constructors = element.constructors;
  -    List<ConstructorElement> members =
  -        new List<ConstructorElement>(constructors.length);
  -    for (int i = 0; i < constructors.length; i++) {
  -      members[i] = ConstructorMember.from(constructors[i], this);
  -    }
  -    return members;
  +    if (_constructors == null) {
  +      List<ConstructorElement> constructors = element.constructors;
  +      List<ConstructorElement> members =
  +          new List<ConstructorElement>(constructors.length);
  +      for (int i = 0; i < constructors.length; i++) {
  +        members[i] = ConstructorMember.from(constructors[i], this);
  +      }
  +      _constructors = members;
  +    }
  +    return _constructors;
     }
   
     @override
  
positive.code:   final List<FunctionTypeAliasElement> prunedTypedefs;
  
    /**
     * Initialize a newly created type to be declared by the given [element].
     */
    InterfaceTypeImpl(ClassElement element, [this.prunedTypedefs])
  
negative.code: 
    @override
    List<MethodElement> get methods {
      if (_methods == null) {
        List<MethodElement> methods = element.methods;
        List<MethodElement> members = new List<MethodElement>(methods.length);
        for (int i = 0; i < methods.length; i++) {
          members[i] = MethodMember.from(methods[i], this);
        }
        _methods = members;
      }
      return _methods;
    }
  
    @override
  