### Question:
IdBitMap extends RangeBitmap { @Override public byte[] toBytes() { return ByteBuffer.allocate(5) .order(ByteOrder.LITTLE_ENDIAN) .put(getType().getHead()) .putInt(start).array(); } private  IdBitMap(int id); int getId(); static ImmutableBitMap of(int id); @Override ImmutableBitMap getAnd(ImmutableBitMap index); @Override ImmutableBitMap getOr(ImmutableBitMap index); @Override ImmutableBitMap clone(); @Override BitMapType getType(); @Override byte[] toBytes(); @Override String toString();  }### Answer:
@Test public void toBytes() { assertArrayEquals(IdBitMap.of(1).toBytes(), ByteBuffer.allocate(5).order(ByteOrder.LITTLE_ENDIAN) .put(BitMapType.ID.getHead()).putInt(1).array()); }