etcdserver/server.go
func (s *EtcdServer) ReportSnapshot(id uint64, status raft.SnapshotStatus) {
	s.r.ReportSnapshot(id, status)
}
func (s *EtcdServer) ReportSnapshot(id uint64, status raft.SnapshotStatus) {
	s.r.ReportSnapshot(id, status)
}
// ReportSnapshot reports snapshot sent status to the raft state machine,
// and clears the used snapshot from the snapshot store.