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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(self):
 """Start the workers."""

        if self.num_workers:
            self.queue = Queue(maxsize=self.num_workers)
            self.workers = [_Worker(self) for _ in range(self.num_workers)]
            for worker in self.workers:
                worker.start()
        self.running = True