getting Location from "getAvailabilityFor" Calendar items

[Traxxas10]

Hello,
I'm looking in the calendar of a different user on the same exchange server for his free/busy items without any no problem:

$api = API::withUsernameAndPassword($server,$username ,$password, ['timezone' => 'W. Europe Standard Time']);
$calendar = $api->getCalendar();

$availability = $calendar->getAvailabilityFor($startdate, $enddate, [$email]);

$items = $availability->getFreeBusyResponseArray()->FreeBusyResponse->getFreeBusyView()->getCalendarEventArray()->CalendarEvent;

but now, he booked his meetings in different locations(Rooms) and I want to get this information with this library too.
whats the easiest way to do that?

if I'm looking at the $items details, I just can see the start, end, free/busy and details, but details are protected?

print_r($items);

output:
Array ( [0] => garethp\ews\API\Type\CalendarEventType Object ( [startTime:protected] => 2020-02-28T09:00:00 [_typeMap:protected] => Array ( [startTime] => dateTime [endTime] => dateTime ) [endTime:protected] => 2020-02-28T20:30:00 [busyType:protected] => Free [calendarEventDetails:protected] => [_] => [_value] => )...

best regards