public static function toLevel($arg, $defaultLevel = null) {
		if(is_int($arg)) {
			switch($arg) {
				case self::ALL:	return self::getLevelAll();
				case self::TRACE: return self::getLevelTrace();
				case self::DEBUG: return self::getLevelDebug();
				case self::INFO: return self::getLevelInfo();
				case self::WARN: return self::getLevelWarn();
				case self::ERROR: return self::getLevelError();
				case self::FATAL: return self::getLevelFatal();
				case self::OFF:	return self::getLevelOff();
				default: return $defaultLevel;
			}
		} else {
			switch(strtoupper($arg)) {
				case 'ALL':	return self::getLevelAll();
				case 'TRACE': return self::getLevelTrace();
				case 'DEBUG': return self::getLevelDebug();
				case 'INFO': return self::getLevelInfo();
				case 'WARN': return self::getLevelWarn();
				case 'ERROR': return self::getLevelError();
				case 'FATAL': return self::getLevelFatal();
				case 'OFF':	return self::getLevelOff();
				default: return $defaultLevel;
			}
		}
	}