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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 start(cls, originator_id, quorum_size, network_uid):
 """ Factory method that returns a new Paxos aggregate. """

        assert isinstance(quorum_size, int), "Not an integer: {}".format(quorum_size)
        return cls.__create__(
            event_class=cls.Started,
            originator_id=originator_id,
            quorum_size=quorum_size,
            network_uid=network_uid
        )