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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:
 async def extend(self, additional_time):
 """ Adds more time to an already acquired lock. ``additional_time`` can be specified as an integer or a float, both representing the number of seconds to add. """

        if self.local.token is None:
            raise LockError("Cannot extend an unlocked lock")
        if self.timeout is None:
            raise LockError("Cannot extend a lock with no timeout")
        return await self.do_extend(additional_time)