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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 is_blackout(self) -> bool: """Does this alert match a blackout period?"""

        if not current_app.config['NOTIFICATION_BLACKOUT']:
            if self.severity in current_app.config['BLACKOUT_ACCEPT']:
                return False
        return db.is_blackout_period(self)