code: def create(self, identifier, friendly_name=values.unset,
                 proxy_identifier=values.unset, proxy_identifier_sid=values.unset):
          
          data = values.of({
              'Identifier': identifier,
              'FriendlyName': friendly_name,
              'ProxyIdentifier': proxy_identifier,
              'ProxyIdentifierSid': proxy_identifier_sid,
          })
  
          payload = self._version.create(
              'POST',
              self._uri,
              data=data,
          )
  
          return ParticipantInstance(
              self._version,
              payload,
              service_sid=self._solution['service_sid'],
              session_sid=self._solution['session_sid'],
          )
docs: Create a new ParticipantInstance
  
          :param unicode identifier: The phone number of the Participant
          :param unicode friendly_name: The string that you assigned to describe the participant
          :param unicode proxy_identifier: The proxy phone number to use for the Participant
          :param unicode proxy_identifier_sid: The Proxy Identifier Sid
  
          :returns: Newly created ParticipantInstance
          :rtype: twilio.rest.proxy.v1.service.session.participant.ParticipantInstance