func Errorf(format string, args ...interface{}) {
	logger.Output(2, LevelError, fmt.Sprintf(format, args...))
}
func Errorf(format string, args ...interface{}) {
	logger.Output(2, LevelError, fmt.Sprintf(format, args...))
}
func Errorf ( format string , args ... interface { } ) { logger . Output ( 2 , LevelError , fmt . Sprintf ( format , args ... ) ) }
// Errorf records the log with error level
Errorf records the log with error level