docs: public void setMask(byte[] mask) {
      if (mask == null) {
        throw new IllegalArgumentException("Transmitter mask cannot be null.");
      }
      if (mask.length != TRANSMITTER_ID_SIZE) {
        throw new IllegalArgumentException(String.format(
            "Transmitter mask must be %d bytes long.",
            Integer.valueOf(TRANSMITTER_ID_SIZE)));
      }
      this.mask = mask;
    }