$content_header =<<<CONTENT_HEADER            <section class="content-header">                <h1>                    $this->page_title                </h1>                <ol class="breadcrumb">                    <li><a href=http://www.mamicode.com/"__SITE__">class="fa fa-dashboard"></i> 首页</a></li>                    $breadcrumb                </ol>            </section>    CONTENT_HEADER;