anchor.diff:      if (linkedNode != null) {
         linkedContext.setReturnType(linkedNode, returnType);
       }
  -    _returnType = _checkElementOfType(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.
  
positive.code:   /// [returnType].
    @override
    set returnType(DartType returnType) {
      _returnType = _checkElementOfType(returnType);
    }
  
    @override
  
negative.code:     return annotations;
    }
  
    /// 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].
  