Asserts that the specified comment does not have a link to a parent.
@parm int $cid The comment ID to check.
protected function assertNoParentLink($cid) {
// This pattern matches a markup structure like:
// <a id="comment-2"></a>
// <article>
// <p class="parent"></p>
// </article>
$pattern = "//a[@id='comment-{$cid}']/following-sibling::article//p[contains(@class, 'parent')]";
$this
->assertNoFieldByXpath($pattern, NULL, format_string('Comment %cid does not have a link to a parent.', array(
'%cid' => $cid,
)));
}