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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, execution_history, backward_execution=False, generate_run_id=True):
 """ Starts the execution of the state in a new thread. :return: """

        self.execution_history = execution_history
        if generate_run_id:
            self._run_id = run_id_generator()
        self.backward_execution = copy.copy(backward_execution)
        self.thread = threading.Thread(target=self.run)
        self.thread.start()