Cloud Datastore Client - Class Entity (1.19.0)

 use Google\Cloud\Datastore\DatastoreClient;

$datastore = new DatastoreClient();

$key = $datastore->key('Person', 'Bob');
$entity = $datastore->entity($key, [
    'firstName' => 'Bob',
    'lastName' => 'Testguy'
]);

$firstName = $entity['firstName']; // 'Bob'
$entity['location'] = 'Detroit, MI'; 

 // Custom entity types can be created by implementing the datastore entity interface.
// You can also define mappings to correctly fetch embedded entities.
use Google\Cloud\Datastore\EntityTrait;
use Google\Cloud\Datastore\EntityInterface;

class Business implements EntityInterface
{
    use EntityTrait;

    public static function mappings()
    {
        return [
            'parent' => Business::class
        ];
    }
}

$alphabet = new Business;
$alphabet->set([
    'companyName' => 'Alphabet'
]);

$key = $datastore->key('Business', 'Google');
$google = $datastore->entity($key, [
    'companyName' => 'Google',
    'parent' => $alphabet
], [
    'className' => Business::class
]);

$datastore->insert($google);

$google = $datastore->lookup($key, ['className' => Business::class]);
echo get_class($google); // `Business`
echo get_class($google->get()['parent']); // `Business`