@Test
 public void testMixedCase() throws Exception {
   HexDecoder hd = new HexDecoder();
   ByteBuffer bb = hd.code(CharBuffer.wrap("00AAaaAaaA99"));
   Assert.assertEquals(0, bb.get());
   Assert.assertEquals((byte) 0xAA, bb.get());
   Assert.assertEquals((byte) 0xAA, bb.get());
   Assert.assertEquals((byte) 0xAA, bb.get());
   Assert.assertEquals((byte) 0xAA, bb.get());
   Assert.assertEquals((byte) 0x99, bb.get());
   Assert.assertFalse(bb.hasRemaining());
 }
 protected void test(HexDecoder hd, String encoded, byte[] expected) throws Exception {
   ByteBuffer bb = hd.code(CharBuffer.wrap(encoded));
   byte[] actual = new byte[bb.remaining()];
   bb.get(actual);
   Assert.assertArrayEquals(expected, actual);
 }