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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 acquire( self, timeout: Union[float, datetime.timedelta] = None ) -> Awaitable[_ReleasingContextManager]: """Attempt to lock. Returns an awaitable. Returns an awaitable, which raises `tornado.util.TimeoutError` after a timeout. """

        return self._block.acquire(timeout)