Send a command to the physical bridge.

        :param command: A Command instance.
        :param reps: Number of repetitions.
        :param wait: Wait time in seconds.

def send(self, command, reps=REPS, wait=MIN_WAIT):
        """ Send a command to the physical bridge.

        :param command: A Command instance.
        :param reps: Number of repetitions.
        :param wait: Wait time in seconds.
        """
        # Enqueue the command.
        self._command_queue.put((command, reps, wait))
        # Wait before accepting another command.
        # This keeps individual groups relatively synchronized.
        sleep = reps * wait * self.active
        if command.select and self._selected_number != command.group_number:
            sleep += SELECT_WAIT
        time.sleep(sleep)