func (t *transport) RequestVote(id raft.ServerID, target raft.ServerAddress, args *raft.RequestVoteRequest, resp *raft.RequestVoteResponse) error {
	return t.sendRPC(string(target), args, resp)
}
func (t *transport) RequestVote(id raft.ServerID, target raft.ServerAddress, args *raft.RequestVoteRequest, resp *raft.RequestVoteResponse) error {
	return t.sendRPC(string(target), args, resp)
}
// RequestVote sends the appropriate RPC to the target node.