func FailFunc(f func() string) error {
	if isModeEnable(FAIL) {
		return glg.out(FAIL, "%s", f())
	}
	return nil
}
func FailFunc(f func() string) error {
	if isModeEnable(FAIL) {
		return glg.out(FAIL, "%s", f())
	}
	return nil
}
func FailFunc ( f func ( ) string ) error { if isModeEnable ( FAIL ) { return glg . out ( FAIL , " " , f ( ) ) } return nil }
// FailFunc outputs Fail level log returned from the function
FailFunc outputs Fail level log returned from the function