//
        // Create a new configuration object
        $config = HTMLPurifier_Config::createDefault();
        $config->set('Filter.ExtractStyleBlocks', true);
        $config->set('CSS.AllowImportant', true);
        $config->set('CSS.AllowTricky', true);
        $config->set('CSS.Trusted', true);
        $config->set('Cache.SerializerPath', base_path('storage/framework/cache'));
        // Create a new purifier instance
        $purifier = new HTMLPurifier($config);
        // Wrap our CSS in style tags and pass to purifier.
        // we're not actually interested in the html response though
        $purifier->purify('');
        // The "style" blocks are stored seperately
        $css = $purifier->context->get('StyleBlocks');
        // Get the first style block
        return count($css) ? $css[0] : '';
    }
    public static function sanitizeHTML($html)
    {
        $html = html_entity_decode($html);
        $config = HTMLPurifier_Config::createDefault();
        $config->set('Cache.SerializerPath', base_path('storage/framework/cache'));
        $purifier = new HTMLPurifier($config);
        return $purifier->purify($html);
    }
    public static function previousUrl($fallback)
    {
        $previous = url()->previous();
        $current = request()->url();
        if ($previous == $current) {
            return url($fallback);
        } else {
            return $previous;
        }
    }
}