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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 stop(self, wait=True):
        ''' Stop the Bokeh Server.

        This stops and removes all Bokeh Server ``IOLoop`` callbacks, as well
        as stops the ``HTTPServer`` that this instance was configured with.

        Args:
            fast (bool):
                Whether to wait for orderly cleanup (default: True)

        Returns:
            None

        '''
        assert not self._stopped, "Already stopped"
        self._stopped = True
        self._tornado.stop(wait)
        self._http.stop()