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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 _on_context_disconnect(self, context):
 """ Respond to Context disconnect event by deleting any record of the no longer reachable context. This method runs in the Broker thread and must not to block. """

        self._lock.acquire()
        try:
            LOG.info('%r: Forgetting %r due to stream disconnect', self, context)
            self._forget_context_unlocked(context)
        finally:
            self._lock.release()