code: public final static byte[] toByteArray(String uid) {
          byte[] result = new byte[16];
          char[] chars = uid.toCharArray();
          int r = 0;
          for (int i = 0; i < chars.length; ++i) {
              if (chars[i] == '-') {
                  continue;
              }
              int h1 = Character.digit(chars[i], 16);
              ++i;
              int h2 = Character.digit(chars[i], 16);
              result[(r++)] = (byte) ((h1 << 4 | h2) & 0xFF);
          }
          return result;
      }
docs: Returns a byte array for the given uuid or guid.
  
  @param uid
  unique id
  @return array of bytes containing the id