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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 confirm_user(self, user):
 """ Confirms the specified user. Returns False if the user has already been confirmed, True otherwise. :param user: The user to confirm. """

        if user.confirmed_at is not None:
            return False
        user.confirmed_at = self.security.datetime_factory()
        user.active = True
        self.user_manager.save(user)

        user_confirmed.send(app._get_current_object(), user=user)
        return True