### Question:
IdUtils { public static UUID fromBytes(final byte[] b) { if (b == null || b.length != 16) { return null; } final ByteBuffer bb = ByteBuffer.wrap(b); return new UUID(bb.getLong(), bb.getLong()); } IdUtils(); static UUID create(); static UUID tryParse(final String str); static byte[] toBytes(final UUID id); static UUID fromBytes(final byte[] b);  }### Answer:
@Test public void testFromBytesNull() { assertNull(IdUtils.fromBytes(null)); }
@Test public void testFromBytesTooShort() { assertNull(IdUtils.fromBytes(new byte[] { 1, 2, 3 })); }
@Test public void testFromBytesTooLong() { assertNull(IdUtils.fromBytes(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 })); }