FastFeed\Processor\SanitizerProcessor::__construct PHP Method

    public function __construct($cacheDirectory = null)
    {
        if (!$cacheDirectory) {
            $cacheDirectory = realpath(sys_get_temp_dir());
        }
        if (!is_writable($cacheDirectory)) {
            throw new InvalidArgumentException($cacheDirectory . ' is not writable');
        }
        // require to configure some CONSTANST
        new \HTMLPurifier_Bootstrap();
        $config = \HTMLPurifier_Config::createDefault();
        $config->set('Cache.SerializerPath', $cacheDirectory);
        $this->purifier = new \HTMLPurifier($config);
    }