### Question:
Statistics { void add(Statistics statistics) { this.count += statistics.count; this.processed += statistics.processed; this.newDeduced += statistics.newDeduced; this.recommendations += statistics.recommendations; }    }### Answer:
@Test public void testAdd() { Statistics statistics = new Statistics(); statistics.count(); Statistics toAdd = new Statistics(); toAdd.count(); toAdd.newDeduced(); statistics.add(toAdd); assertThat(statistics.getCount()).isEqualTo(2); assertThat(statistics.getNewDeduced()).isEqualTo(1); }