@Test
  public void shouldEmitFirstFieldOfTuple() {
    bolt.execute(tuple, collector);

    verify(tuple, times(1)).getValue(0);
    verify(collector, times(1)).emit(any(Values.class));
  }
  @Test
  public void shouldDeclareOutputFields() {
    bolt.declareOutputFields(declarer);

    verify(declarer, times(1)).declare(any(Fields.class));
  }