LongBitMask extends SingleLongBitMask implements BitMask { @Override public boolean isSet(int index) { long bit = 1L << index; return (mask & bit) == bit; } LongBitMask();  LongBitMask(long mask); @Override BitMask set(int index); @Override BitMask setAll(BitMask mask); @Override BitMask reset(int index); @Override BitMask resetAll(BitMask mask); @Override boolean isSet(int index); @Override boolean isAllSet(); @Override boolean isEmpty(); @Override boolean intersects(BitMask mask); long asLong(); @Override LongBitMask clone(); @Override String getInstancingStatement();  }
@Test public void testIsSet() { Assert.assertFalse(new LongBitMask().set(1).isSet(0)); Assert.assertTrue(new LongBitMask().set(1).isSet(1)); }