raft/rawnode.go
func (rn *RawNode) Ready() Ready {
	rd := rn.newReady()
	rn.raft.msgs = nil
	rn.raft.reduceUncommittedSize(rd.CommittedEntries)
	return rd
}
func (rn *RawNode) Ready() Ready {
	rd := rn.newReady()
	rn.raft.msgs = nil
	rn.raft.reduceUncommittedSize(rd.CommittedEntries)
	return rd
}
// Ready returns the current point-in-time state of this RawNode.