glg.go
func InfoFunc(f func() string) error {
	if isModeEnable(INFO) {
		return glg.out(INFO, "%s", f())
	}
	return nil
}
func InfoFunc(f func() string) error {
	if isModeEnable(INFO) {
		return glg.out(INFO, "%s", f())
	}
	return nil
}
// InfoFunc outputs Info level log returned from the function