code: def participants(self):
          
          if self._participants is None:
              self._participants = ParticipantList(self._version, session_sid=self._solution['sid'], )
          return self._participants
docs: Access the participants
  
          :returns: twilio.rest.messaging.v1.session.participant.ParticipantList
          :rtype: twilio.rest.messaging.v1.session.participant.ParticipantList