raft/log.go
func newLog(storage Storage, logger Logger) *raftLog {
	return newLogWithSize(storage, logger, noLimit)
}
func newLog(storage Storage, logger Logger) *raftLog {
	return newLogWithSize(storage, logger, noLimit)
}
// newLog returns log using the given storage and default options. It
// recovers the log to the state that it just commits and applies the
// latest snapshot.