Remove and return an item from the queue.

        Returns an awaitable which resolves once an item is available, or raises
        `tornado.util.TimeoutError` after a timeout.

        ``timeout`` may be a number denoting a time (on the same
        scale as `tornado.ioloop.IOLoop.time`, normally `time.time`), or a
        `datetime.timedelta` object for a deadline relative to the
        current time.

        .. note::

           The ``timeout`` argument of this method differs from that
           of the standard library's `queue.Queue.get`. That method
           interprets numeric values as relative timeouts; this one
           interprets them as absolute deadlines and requires
           ``timedelta`` objects for relative timeouts (consistent
           with other timeouts in Tornado).

def get(self, timeout: Union[float, datetime.timedelta] = None) -> Awaitable[_T]:
        """Remove and return an item from the queue.

        Returns an awaitable which resolves once an item is available, or raises
        `tornado.util.TimeoutError` after a timeout.

        ``timeout`` may be a number denoting a time (on the same
        scale as `tornado.ioloop.IOLoop.time`, normally `time.time`), or a
        `datetime.timedelta` object for a deadline relative to the
        current time.

        .. note::

           The ``timeout`` argument of this method differs from that
           of the standard library's `queue.Queue.get`. That method
           interprets numeric values as relative timeouts; this one
           interprets them as absolute deadlines and requires
           ``timedelta`` objects for relative timeouts (consistent
           with other timeouts in Tornado).

        """
        future = Future()  # type: Future[_T]
        try:
            future.set_result(self.get_nowait())
        except QueueEmpty:
            self._getters.append(future)
            _set_timeout(future, timeout)
        return future