code: public static byte[] getGuidAsByteArray(final String GUID) {
          final UUID uuid = UUID.fromString(GUID);
  
          final ByteBuffer buff = ByteBuffer.wrap(new byte[16]);
          buff.putLong(uuid.getMostSignificantBits());
          buff.putLong(uuid.getLeastSignificantBits());
  
          byte[] res = new byte[] {
              buff.get(3),
              buff.get(2),
              buff.get(1),
              buff.get(0),
              buff.get(5),
              buff.get(4),
              buff.get(7),
              buff.get(6),
              buff.get(8),
              buff.get(9),
              buff.get(10),
              buff.get(11),
              buff.get(12),
              buff.get(13),
              buff.get(14),
              buff.get(15), };
  
          return res;
      }
docs: Gets GUID as byte array.
  
  @param GUID GUID.
  @return GUID as byte array.