HUSKY - WooCommerce Products Filter Professional

Using in ‘by_‘ extensions for adding its keys in system for to make the extension visible

Example:

add_filter('woof_add_items_keys', array($this, 'woof_add_items_keys'));

public function woof_add_items_keys($keys)
    {
        $keys[] = $this->html_type;
        return $keys;
    }