anchor.diff:      return annotations;
     }
   
  -  /// If the element associated with the given [type] is a generic function type
  -  /// element, then make it a child of this element. Return the [type] as a
  -  /// convenience.
  -  DartType _checkElementOfType(DartType type) {
  -    Element element = type?.element;
  -    if (element is GenericFunctionTypeElementImpl &&
  -        element.enclosingElement == null) {
  -      element.enclosingElement = this;
  -    }
  -    return type;
  -  }
  -
     /// If the given [type] is a generic function type, then the element
     /// associated with the type is implicitly a child of this element and should
     /// be visited by the given [visitor].
  
positive.code:   }
  
    set bound(DartType bound) {
      _bound = _checkElementOfType(bound);
    }
  
    @override
  
negative.code:     if (linkedNode != null) {
        linkedContext.setReturnType(linkedNode, returnType);
      }
      _returnType = returnType;
      // We do this because of return type inference. At the moment when we
      // create a local function element we don't know yet its return type,
      // because we have not done static type analysis yet.
  