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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 next(self):
 """Get the next processable item of the queue. A processable item is supposed to have the status `queued`. Returns: None : If no key is found. Int: If a valid entry is found. """

        smallest = None
        for key in self.queue.keys():
            if self.queue[key]['status'] == 'queued':
                if smallest is None or key < smallest:
                    smallest = key
        return smallest