code: def send_bulk(self, source_address: str, destination_addresses: List[str], message: str,
                   validity_minutes: int = 0) -> List[SendSmsResult]:
          
          session_id = self._get_session_id()
          params = {
              'sessionId': session_id,
              'sourceAddress': source_address,
              'DestinationAddresses': destination_addresses,
              'data': message,
              'validity': validity_minutes,
          }
          all_sms_ids = self._request(SEND_BULK_URL, params, method=METHOD_POST)
  
          ids_per_sms = len(all_sms_ids) / len(destination_addresses)
          results = []
          message_ids = []
          for sms_id in all_sms_ids:
              message_ids.append(sms_id)
  
              if len(message_ids) == ids_per_sms:
                  address = destination_addresses[len(results)]
                  send_result = SendSmsResult(address, message_ids)
                  message_ids = []
                  results.append(send_result)
  
          return results
docs: http://www.devinotele.com/resheniya/dokumentaciya-po-api/http_rest_protocol/Otpravka_SMS-soobshcheny/