code: def _play(self):
          
          # Use pause command only for sources which support NETAUDIO
          if self._input_func in self._netaudio_func_list:
              body = {"cmd0": "PutNetAudioCommand/CurEnter",
                      "cmd1": "aspMainZone_WebUpdateStatus/",
                      "ZoneName": "MAIN ZONE"}
              try:
                  if self.send_post_command(
                          self._urls.command_netaudio_post, body):
                      self._state = STATE_PLAYING
                      return True
                  else:
                      return False
              except requests.exceptions.RequestException:
                  _LOGGER.error("Connection error: play command not sent.")
                  return False
docs: Send play command to receiver command via HTTP post.