protected function setBreadcrumbEditProductClassField()
    {
        $breadcrumbs = array();

        $breadcrumbs[] = array(
            'url' => $this->url('admin'),
            'text' => $this->text('Dashboard')
        );

        $breadcrumbs[] = array(
            'text' => $this->text('Product classes'),
            'url' => $this->url('admin/content/product-class')
        );

        $breadcrumbs[] = array(
            'text' => $this->text('Fields of %name', array('%name' => $this->data_product_class['title'])),
            'url' => $this->url("admin/content/product-class/field/{$this->data_product_class['product_class_id']}")
        );

        $this->setBreadcrumbs($breadcrumbs);
    }