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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 alert(self, msg):
 """Tell anyone who wants to know that a sensor was updated."""

        if self.event_callback is not None:
            try:
                self.event_callback(msg)
            except Exception as exception:  # pylint: disable=broad-except
                _LOGGER.exception(exception)

        if self.persistence:
            self.persistence.need_save = True