/**
 * Returns an atom entry object representing the event with the specified ID.
 *
 * @param Zend_Http_Client $client The authenticated client object
 * @param string $eventId The event ID string
 * @return Zend_Feed_EntryAtom if the event is found, null if it's not
 */
function getAtomEntry($client, $eventId)
{
    $gdataCal = new Zend_Gdata_Calendar($client);
    $gdataCal->setUser('default');
    $gdataCal->setVisibility('private');
    $gdataCal->setProjection('full');
    $gdataCal->setEvent($eventId);
    try {
        $eventFeed = $gdataCal->getCalendarFeed();
        if ($eventFeed->valid()) {
            return $eventFeed->current();
        } else {
            return null;
        }
    } catch (Zend_Feed_Exception $fe) {
        return null;
    }
}