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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 _key(self, additional_key: Any=None) -> str: """Construct a hashable key from this object's state. Parameters additional_key : Any additional information used to seed random number generation. Returns ------- str A key to seed random number generation. """

        return '_'.join([self.key, str(self.clock()), str(additional_key), str(self.seed)])