docs: def flag_forgotten_entries(session, today=None):
      """Flag any entries from previous days where users forgot to sign
      out.
  
      :param session: SQLAlchemy session through which to access the database.
      :param today: (optional) The current date as a `datetime.date` object. Used for testing.
      """ # noqa
      today = date.today() if today is None else today
  
      forgotten = (
          session
          .query(Entry)
          .filter(Entry.time_out.is_(None))
          .filter(Entry.forgot_sign_out.is_(False))
          .filter(Entry.date < today)
      )
  
      for entry in forgotten:
          e = sign_out(entry, forgot=True)
          logger.debug('Signing out forgotten entry: {}'.format(e))
          session.add(e)
  
      session.commit()