public Request listIndexesAsync(@Nullable final RequestOptions requestOptions, @NonNull CompletionHandler completionHandler) {
        return new AsyncTaskRequest(completionHandler) {
            @NonNull
            @Override
            protected JSONObject run() throws AlgoliaException {
                return listIndexes(requestOptions);
            }
        }.start();
    }
public Request listIndexesAsync(@Nullable final RequestOptions requestOptions, @NonNull CompletionHandler completionHandler) {
        return new AsyncTaskRequest(completionHandler) {
            @NonNull
            @Override
            protected JSONObject run() throws AlgoliaException {
                return listIndexes(requestOptions);
            }
        }.start();
    }
public Request listIndexesAsync ( @ Nullable final RequestOptions requestOptions , @ NonNull CompletionHandler completionHandler ) { return new AsyncTaskRequest ( completionHandler ) { @ NonNull @ Override protected JSONObject run ( ) throws AlgoliaException { return listIndexes ( requestOptions ) ; } } . start ( ) ; }
List existing indexes.

@param requestOptions    Request-specific options.
@param completionHandler The listener that will be notified of the request's outcome.
@return A cancellable request.
List existing indexes .