use Bookingcom\Client\Client;
use Bookingcom\Client\Result\ChangedHotels;

$client = new Client('<username>', '<password>');
$client->getChangedHotels('-2 hours')->then(function (ChangedHotels $changedHotels) {
    foreach ($changedHotels->getClosedHotelIds() as $hotelId) {
        // do something
    }
    
    // or
    foreach ($changedHotels->getChanges() as $hotelId => $changes) {
        // do something
    }
})->wait();

use GuzzleHttp\Promise;
use Bookingcom\Client\Client;

$client = new Client('<username>', '<password>');

$results = Promise\all([
    'descriptions' => $client->getHotelDescriptions(42, ['en', 'nl']),
    'facilities' => $client->getHotelFacilities(42, ['en', 'nl']),
])->wait();

foreach ($results as $type => $result) {
    // ...
}