kubernetes/vendor/go.etcd.io/etcd/server/v3/etcdserver/api/membership/confstate.go

var confStateKey …

// MustUnsafeSaveConfStateToBackend persists confState using given transaction (tx).
// confState in backend is persisted since etcd v3.5.
func MustUnsafeSaveConfStateToBackend(lg *zap.Logger, tx backend.BatchTx, confState *raftpb.ConfState) { … }

// UnsafeConfStateFromBackend retrieves ConfState from the backend.
// Returns nil if confState in backend is not persisted (e.g. backend writen by <v3.5).
func UnsafeConfStateFromBackend(lg *zap.Logger, tx backend.ReadTx) *raftpb.ConfState { … }