code: def add_parallel_gateway_to_diagram(self, process_id, gateway_name="", gateway_direction="Unspecified",
                                          node_id=None):
          
          parallel_gateway_id, parallel_gateway = self.add_gateway_to_diagram(process_id,
                                                                              consts.Consts.parallel_gateway,
                                                                              gateway_name=gateway_name,
                                                                              gateway_direction=gateway_direction,
                                                                              node_id=node_id)
          return parallel_gateway_id, parallel_gateway
docs: Adds an parallelGateway element to BPMN diagram.
  
          :param process_id: string object. ID of parent process,
          :param gateway_name: string object. Name of inclusive gateway,
          :param gateway_direction: string object. Accepted values - "Unspecified", "Converging", "Diverging", "Mixed".
              Default value - "Unspecified",
          :param node_id: string object. ID of node. Default value - None.
  
          :return: a tuple, where first value is parallelGateway ID, second a reference to created object.