function update($new_instance, $old_instance)
 {
     $instance = parent::update($new_instance, $old_instance);
     $instance['cols_per_row'] = (int) strip_tags($new_instance['cols_per_row']);
     $instance['excerpt_words_limit'] = isset($new_instance['excerpt_words_limit']) ? (int) $new_instance['excerpt_words_limit'] : 0;
     $instance['is_show_date'] = isset($new_instance['is_show_date']) ? 1 : 0;
     $instance['is_show_comments'] = isset($new_instance['is_show_comments']) ? 1 : 0;
     return $instance;
 }