_initializeValidFacilities example

    public function setFacility($facility)
    {
        if ($this->_facility === $facility) {
            return $this;
        }

        if (!count($this->_validFacilities)) {
            $this->_initializeValidFacilities();
        }

        if (!in_array($facility, $this->_validFacilities)) {
            throw new Zend_Log_Exception('Invalid log facility provided; please see http://php.net/openlog for a list of valid facility values');
        }

        if ('WIN' == strtoupper(substr(PHP_OS, 0, 3))
            && ($facility !== LOG_USER)
        ) {
            throw new Zend_Log_Exception('Only LOG_USER is a valid log facility on Windows');
        }