// display widget
    function widget($args, $instance) {

      extract( $args );

      // get widget title
      $title           = apply_filters('widget_title', $instance['title']);

      //  get options
      $token         = $instance['token'];
      $tags           = $instance['tags'];
      $unread       = $instance['unread'];
      $range         = $instance['range'];

      // update linklist based on cache validity
      $isvalid = $this->_check_valid_cache( $instance['expires'], $range );
      if ( $isvalid === TRUE ) {
        $cache         = $instance['cache'];
        $expires       = $instance['expires'];
      } else {
        $cache         = $this->_get_recent( $token );
        $expires       = $isvalid;
        --> does not work!!
        $this->update($instance, $instance);
      }
      ...display widget...

    }