public Map<Endpoint, CompletableFuture<Void>> futures() {
        return futures;
    }
@Test
    public void testImmediateCompletion() {
        EndpointReadyFutures readyFutures = new EndpointReadyFutures.Builder().
                build(Optional.empty(), INFO);
        assertEquals(new HashSet<>(Arrays.asList(EXTERNAL, INTERNAL)),
                readyFutures.futures().keySet());
        assertComplete(readyFutures, EXTERNAL, INTERNAL);
    }