public static HandlerFactory<AsyncPushConsumer> pushRouter(final RequestRouter<Supplier<AsyncPushConsumer>> requestRouter) {
        return (request, context) -> {
            final Supplier<AsyncPushConsumer> supplier = requestRouter.resolve(request, context);
            return supplier != null ? supplier.get() : null;
        };
    }
Creates {@link HandlerFactory} backed by a push {@link RequestRouter}.

@since 5.4
httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClients.java