/**
* Filter list by urls matching a regular expression
*
* @param string $regexp
* @return Zend_Service_Delicious_PostList
*/
public function withUrl($regexp)
{
$postList = new self($this->_service);
foreach ($this->_posts as $post) {
if (preg_match($regexp, $post->getUrl())) {
$postList->_addPost($post);
}
}
return $postList;
}