http/log/log.go
func CommonLogHandler(logger *log.Logger, templ string, h http.Handler) http.Handler {
	if logger == nil {
		logger = log.New(os.Stdout, "", 0)
	}
	if templ == "" {
		templ = CommonLogFormat
	}

	return &commonLogHandler{
		handler:  h,
		logger:   logger,
		template: template.Must(template.New("").Parse(templ)),
	}
}
func CommonLogHandler(logger *log.Logger, templ string, h http.Handler) http.Handler {
	if logger == nil {
		logger = log.New(os.Stdout, "", 0)
	}
	if templ == "" {
		templ = CommonLogFormat
	}

	return &commonLogHandler{
		handler:  h,
		logger:   logger,
		template: template.Must(template.New("").Parse(templ)),
	}
}
// CommonLogHandler returns a handler that serves HTTP requests
// If a logger is not provided, stdout will be used