private function parseFacility() {
		if (!empty($this->facility)) {   
			$constant = "LOG_" . trim($this->facility);
			if (defined($constant)) {
				return constant($constant);
			} else {
				throw new \n2n\log4php\LoggerException("log4php: Invalid syslog facility provided: {$this->facility}.", E_USER_WARNING);
			}
		}
	}