assertThat(Longs.ensureCapacity(ARRAY1, 1, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Longs.ensureCapacity(ARRAY1, 2, 1)).isEqualTo(new long[] {1L, 0L, 0L});
  }

  public void testEnsureCapacity_fail() {
    assertThrows(IllegalArgumentException.class, () -> Longs.ensureCapacity(ARRAY1, -1, 1));
    assertThrows(IllegalArgumentException.class, () -> Longs.ensureCapacity(ARRAY1, 1, -1));
  }