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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 run_actor(self, actor):
        '''Start running the ``actor``.
        '''
        set_actor(actor)
        if not actor.mailbox.address:
            address = ('127.0.0.1', 0)
            actor._loop.create_task(
                actor.mailbox.start_serving(address=address)
            )
        actor._loop.run_forever()