### Question:
LongList { public void addAll(LongList other) { ensureCapacity(size + other.size); System.arraycopy(other.longs, 0, longs, size, other.size); size += other.size; } LongList();  LongList(int initialCapacity); static LongList of(long... values); void add(long l); void addAll(LongList other); int getSize(); long get(int i); boolean contains(long l); boolean remove(long l); long remove(int i); void clear(); @Override String toString(); long[] toArray(); boolean isEmpty();  }### Answer:
@Test void testAddAll() { longList.add(42); LongList list2 = new LongList(); list2.add(43); list2.add(44); longList.addAll(list2); assertThat(this.longList.getSize()).isEqualTo(3); assertThat(this.longList.get(0)).isEqualTo(42); assertThat(this.longList.get(1)).isEqualTo(43); assertThat(this.longList.get(2)).isEqualTo(44); }