replication.go
func (s *followerReplication) cleanNotify(v *verifyFuture) {
	s.notifyLock.Lock()
	delete(s.notify, v)
	s.notifyLock.Unlock()
}
func (s *followerReplication) cleanNotify(v *verifyFuture) {
	s.notifyLock.Lock()
	delete(s.notify, v)
	s.notifyLock.Unlock()
}
// cleanNotify is used to delete notify, .