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