log_nix.go
func NewLogBackend(out io.Writer, prefix string, flag int) *LogBackend {
	return &LogBackend{Logger: log.New(out, prefix, flag)}
}
func NewLogBackend(out io.Writer, prefix string, flag int) *LogBackend {
	return &LogBackend{Logger: log.New(out, prefix, flag)}
}
// NewLogBackend creates a new LogBackend.