anchor.diff:          handleData, handleDiff, 'diff');
       Communicator dataCommunicator = new Communicator(connection, 'months',
           handleData, handleDiff, 'data');
  -    Map response_data, response_diff, empty_diff;
  +    Map data, diff, emptyDiff;
   
       setUp(() {
         connection = new ConnectionMock();
         handleData = new FunctionMock();
         handleDiff = new FunctionMock();
  -      response_data = {'data': 'some_data', 'version': 12};
  -      response_diff = {'diff': [{'version': 13}, {'version': 14}]};
  -      empty_diff = {'diff': []};
  +      data = {'data': 'some_data', 'version': 12};
  +      diff = {'diff': [{'version': 13}, {'version': 14}]};
  +      emptyDiff = {'diff': []};
       });
   
       test("get_data sent after start.", () {
         // given
         connection.when(callsTo('sendRequest')).thenCall((_) {
           defaultCommunicator.stop();
  -        return new Future.value(response_data);
  +        return new Future.value(data);
         });
         handleData = new FunctionMock();
         defaultCommunicator = new Communicator(connection, 'months', handleData,
  
positive.code:       // given
        connection.when(callsTo('sendRequest')).thenCall((_) {
          defaultCommunicator.stop();
          return new Future.value(response_data);
        });
        defaultCommunicator = new Communicator(connection, 'months', handleData,
            handleDiff);
  
negative.code:     test("handleDiff called properly.", () {
        // given
        connection.when(callsTo('sendRequest')).thenCall((_) {
          return new Future.value(data);
        }).thenCall((_) {
          defaultCommunicator.stop();
          return new Future.value(diff);
        });
        defaultCommunicator = new Communicator(connection, 'months', handleData,
            handleDiff);
  