@Test
public void testCompositeBitmask() {

  // generate composite bitmask for 3 bitmasks and ensure correctness
  final byte[] bitmask =
      BitmaskUtils.generateCompositeBitmask(new TreeSet<>(Arrays.asList(0, 1, 2)));
  Assert.assertTrue(BitSet.valueOf(bitmask).equals(composite_0_1_2));
}