code: public byte[] toByteArray() {
          ByteArrayOutputStream outputStream = new ByteArrayOutputStream(32);
  
          outputStream.write(commandByte);
  
          if (serialize(outputStream)) {
              return outputStream.toByteArray();
          }
  
          return null;
      }
docs: Combine the CommandByte and the serialized message packet together to form a Firmata supported
  byte packet to be sent over the SerialPort.
  
  @return true if no errors building message