<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def expiration_time(self):
 """ Returns the time until this access attempt is forgotten. """

        logging_forgotten_time = configuration.behavior.login_forgotten_seconds

        if logging_forgotten_time <= 0:
            return None

        now = timezone.now()
        delta = now - self.modified
        time_remaining = logging_forgotten_time - delta.seconds

        return time_remaining