logger.go
func (l *Logger) Panicf(format string, args ...interface{}) {
	l.log(CRITICAL, &format, args...)
	panic(fmt.Sprintf(format, args...))
}
func (l *Logger) Panicf(format string, args ...interface{}) {
	l.log(CRITICAL, &format, args...)
	panic(fmt.Sprintf(format, args...))
}
// Panicf is equivalent to l.Critical followed by a call to panic().