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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 port(self):
 """ Allocate either the requested port or a random empty port for use by application """

        if 'port' not in self.state:
            sock = socket.socket()
            sock.bind(('', self.requested_port))
            self.state['port'] = sock.getsockname()[1]
            sock.close()
        return self.state['port']