glg.go
func PrintFunc(f func() string) error {
	if isModeEnable(PRINT) {
		return glg.out(PRINT, "%s", f())
	}
	return nil
}
func PrintFunc(f func() string) error {
	if isModeEnable(PRINT) {
		return glg.out(PRINT, "%s", f())
	}
	return nil
}
// PrintFunc outputs Print log returned from the function