protected function _validateSlug($instance)
    {
        $slug = $instance->get('eav_attribute')->get('name');
        $columns = $this->_table->schema()->columns();
        if (in_array($slug, $columns)) {
            $instance->get('eav_attribute')->errors('name', __d('field', 'The name "{0}" cannot be used as it collides with table column names.', $slug));
        }
    }