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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 _get_and_set_reconnection_handler(self, new_handler):
 """ Called by the _ControlReconnectionHandler when a new connection is successfully created. Clears out the _reconnection_handler on this ControlConnection. """

        with self._reconnection_lock:
            old = self._reconnection_handler
            self._reconnection_handler = new_handler
            return old