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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 _set_closed(self, future):
 """ Indicate that the instance is effectively closed. :param future: The close future. """

        logger.debug("%s[%s] closed.", self.__class__.__name__, id(self))
        self.on_closed.emit(self)
        self._closed_future.set_result(future.result())