static <V> HttpResponse.MultiSubscriber<MultiMapResult<V>,V>
asMap(Function<HttpRequest,Optional<HttpResponse.BodyHandler<V>>> reqHandler)
asMap(Function<HttpRequest,Optional<HttpResponse.BodyHandler<V>>> reqHandler, boolean completion)
abstract <U,T> CompletableFuture<U>
sendAsync(HttpRequest req, HttpResponse.MultiSubscriber<U,T> multiSubscriber)