code: def _send_str(self, cmd, args):
          
          logger.debug("{} {}".format(cmd, args))
          args = args.encode('utf-8')
  
          le_args_len = self._little_endian(len(args))
          data = cmd.encode() + le_args_len + args
          logger.debug("Send string: {}".format(data))
          self.connection.write(data)
docs: Format:
              {Command}{args length(little endian)}{str}
          Length:
              {4}{4}{str length}