Ensures that a list of nodes appear on the page.
array $expected_nids: An array of node IDs.
protected function assertNids(array $expected_nids = array()) {
$result = $this
->xpath('//span[@class="field-content"]');
$nids = array();
foreach ($result as $element) {
$nids[] = (int) $element;
}
$this
->assertEqual($nids, $expected_nids);
}