algoliasearch/src/main/java/com/algolia/search/saas/Index.java
public Request getObjectsAsync(final @NonNull Collection<String> objectIDs, @Nullable CompletionHandler completionHandler) {
        return getObjectsAsync(objectIDs, /* attributesToRetrieve: */ null, /* requestOptions: */ null, completionHandler);
    }
public Request getObjectsAsync(final @NonNull Collection<String> objectIDs, @Nullable CompletionHandler completionHandler) {
        return getObjectsAsync(objectIDs, /* attributesToRetrieve: */ null, /* requestOptions: */ null, completionHandler);
    }
Gets several objects from this index (asynchronously).

@param objectIDs         Identifiers of objects to retrieve.
@param completionHandler The listener that will be notified of the request's outcome.
@return A cancellable request.