protected function updateListProductClassField()
    {
        $this->controlAccess('product_class_edit');

        foreach ((array) $this->setSubmitted('fields') as $id => $field) {

            if (!empty($field['remove'])) {
                $this->product_class_field->delete($id);
                continue;
            }

            $field['required'] = !empty($field['required']);
            $field['multiple'] = !empty($field['multiple']);
            $this->product_class_field->update($id, $field);
        }

        $this->redirect('', $this->text('Product class has been updated'), 'success');
    }