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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_parallel_gateway_to_diagram(self, process_id, gateway_name="", gateway_direction="Unspecified", node_id=None):
 """ 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. """

        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