docs: public static void encodeSingle(final int input, final byte[] output,
                                      final int outoff) {
  
          if (output == null) {
              throw new NullPointerException("output");
          }
  
          if (outoff < 0) {
              throw new IllegalArgumentException("outoff(" + outoff + ") < 0");
          }
  
          if (outoff >= output.length - 1) {
              throw new IllegalArgumentException(
                  "outoff(" + outoff + ") >= output.length(" + output.length
                  + ") - 1");
          }
  
          output[outoff] = (byte) encodeHalf((input >> 4) & 0x0F);
          output[outoff + 1] = (byte) encodeHalf(input & 0x0F);
      }