code: func (u *UniqueSession) Init() error {
  	session.OnSessionBind(func(ctx context.Context, s *session.Session) error {
  		oldSession := session.GetSessionByUID(s.UID())
  		if oldSession != nil {
  			return oldSession.Kick(ctx)
  		}
  		err := u.rpcClient.BroadcastSessionBind(s.UID())
  		return err
  	})
  	return nil
  }
docs: // Init initializes the module