docs: def delete_user_sessions(user):
      """Delete all active user sessions.
  
      :param user: User instance.
      :returns: If ``True`` then the session is successfully deleted.
      """
      with db.session.begin_nested():
          for s in user.active_sessions:
              _sessionstore.delete(s.sid_s)
  
          SessionActivity.query.filter_by(user=user).delete()
  
      return True