anchor.diff:  
     @override
     DartType get returnType {
  -    if (linkedNode != null) {
  -      if (_returnType != null) return _returnType;
  +    if (_returnType != null) return _returnType;
  +
  +    if (linkedNode != null) {
         var context = enclosingUnit.linkedContext;
         return _returnType = context.getReturnType(linkedNode);
       }
  -    return _returnType ?? _declaredReturnType;
  +    return _returnType;
     }
   
     void set returnType(DartType returnType) {
  
positive.code:       return linkedContext.getCodeOffset(linkedNode);
      }
      return super.codeOffset;
    }
  
    void set declaredReturnType(DartType returnType) {
      _declaredReturnType = _checkElementOfType(returnType);
    }
  
    @override
  
negative.code:   /// element.
    List<ParameterElement> _parameters;
  
    /// The inferred return type of this executable element.
    DartType _returnType;
  
  