htmlpurifier 怎么支持embed标签？?报错

<?php
    require_once 'htmlpurifier-4.6.0/library/HTMLPurifier.includes.php';
    $config = HTMLPurifier_Config::createDefault();
    $config->set('HTML.AllowedElements', array('div'=>true,'p'=>true,'embed'=>true)); //允许属性
    $config->set('HTML.Doctype', 'XHTML 1.0 Transitional');
    $config->set('Core.Encoding', 'UTF-8');

    $dirty_html ='<div> <div style="width: 50px;height: 100px"><div></div></div></div><p>结束测试 aa</p><span>cccccccccccccc</span><embed src="aaa.mp3" width="300" height="220">111111111sdas2222</embed>';
    $purifier = new HTMLPurifier($config);
    $puri_html = $purifier->purify($dirty_html); //搞定~！
    echo $puri_html;

?>