func Errorf(format string, args ...interface{}) {
	if Log != nil {
		Log.Error(fmt.Sprintf(format, args...))
	}
}
func Errorf(format string, args ...interface{}) {
	if Log != nil {
		Log.Error(fmt.Sprintf(format, args...))
	}
}
// Errorf logs at the ERROR log level using a standard printf format string