anchor.diff:    }
   
     Map<Symbol, TypeVariableMirror> _typeVariables = null;
  -
     Map<Symbol, TypeVariableMirror> get typeVariables {
       if (_typeVariables == null) {
         List params = _ClassMirror_type_variables(_reflectee);
  
positive.code:     return _getters;
    }
  
    Map<Symbol, MethodMirror> get setters {
      if (_setters == null) {
        _setters = _filterMap(
  
negative.code:     return _owner;
    }
  
    SourceLocation get location {
      throw new UnimplementedError('TypedefMirror.location is not implemented');
    }
  
    TypeMirror _referent = null;
  