code: String getHexString() {
          final ByteBuffer bytes = getBytes();
          final byte[] array = new byte[bytes.remaining()];
          bytes.get(array);
          final StringBuilder sb = new StringBuilder();
          for (byte b : array) {
              sb.append(String.format("%02x ", b));
          }
          return sb.toString();
      }
docs: Formats the bytes that make up this field as a hex string, for use by subclasses in their {@link #toString()}
  methods.
  
  @return the hex representations of the bytes that this field will send over the network.