public function add($link_info = array())
    {

        if( ! isset($link_info['url']) ) {
            throw new NoItemException("The url is required when adding a link");
        }

        $base_info  = array(
            'action'        => 'add',
            'time'          => time()
        );

        $link_info = array_merge($base_info, $link_info);

        $this->actions[] = $link_info;

        return true;

    }