logging.go
func (logger *Logger) Alertf(format string, a ...interface{}) {
	logger.log(ALERT, format, a...)
}
func (logger *Logger) Alertf(format string, a ...interface{}) {
	logger.log(ALERT, format, a...)
}
func ( logger * Logger ) Alertf ( format string , a ... interface { } ) { logger . log ( ALERT , format , a ... ) }
// Alertf logs provided message with formatting in ALERT level.
Alertf logs provided message with formatting in ALERT level .