Ensures that node_feed() accepts and prints extra channel elements.
function testNodeFeedExtraChannelElements() {
$response = node_feed(array(), array(
'copyright' => 'Drupal is a registered trademark of Dries Buytaert.',
));
$this
->assertTrue(strpos($response
->getContent(), '<copyright>Drupal is a registered trademark of Dries Buytaert.</copyright>') !== FALSE);
}