GetRooms();

$ews = API::withUsernameAndPassword('outlook.office365.com','xxx','xxx');

$request = array(
        'RoomList' => array(
                'EmailAddress' => 'biurowiec@xxx.onmicrosoft.com'
            )

);
$request = API\Type\RoomType::buildFromArray($request);
$response = $ews->getClient()->GetRooms($request);
var_dump($response);