### Question:
Statistics { public void add(Statistics statistics) { this.invalid += statistics.invalid; this.notSupported += statistics.notSupported; this.newDeduced += statistics.newDeduced; this.found += statistics.found; this.validated += statistics.validated; this.groupedValidations += statistics.groupedValidations; this.rounds += statistics.rounds; }  void add(Statistics statistics); void found(); void groupedValidation(); void invalid(); void newDeduced(); void notSupported(); void round(); void validated();  }### Answer:
@Test public void testAdd() { Statistics statistics = new Statistics(); statistics.found(); statistics.invalid(); statistics.newDeduced(); Statistics toAdd = new Statistics(); toAdd.found(); toAdd.found(); toAdd.invalid(); toAdd.validated(); toAdd.groupedValidation(); toAdd.groupedValidation(); toAdd.round(); statistics.add(toAdd); assertThat(statistics.getRounds()).isEqualTo(1); assertThat(statistics.getInvalid()).isEqualTo(2); assertThat(statistics.getNewDeduced()).isEqualTo(1); assertThat(statistics.getNotSupported()).isEqualTo(0); assertThat(statistics.getFound()).isEqualTo(3); assertThat(statistics.getValidated()).isEqualTo(1); assertThat(statistics.getGroupedValidations()).isEqualTo(2); }