public static function getFacebookClient()
 {
     if (self::$client === null) {
         self::$client = new Facebook(self::getApiKey(), self::getApiSecret());
     }
     if (!self::$client) {
         error_log('Could not create facebook client.');
     }
     return self::$client;
 }
 public static function getFacebookClient()
 {
     if (self::$client === null) {
         $params = array('appId' => self::getApiKey(), 'secret' => self::getApiSecret(), 'cookie' => self::getApiCookie(), 'domain' => self::getApiDomain());
         self::$client = new Facebook($params);
     }
     if (!self::$client) {
         error_log('Could not create facebook client.');
     }
     return self::$client;
 }