Returning any error will also cancel the stream remotely.

CAREFUL: When utilizing two-way communication, it is important to ensure that the remote handler is not blocked on a send.
If the remote handler is blocked on a send, and the client is trying to send without the remote receiving, 
the operation would become deadlocked if the channels are full.

### Typed handlers

  private static final long SMALL_TIMEOUT_MILLIS = 10;

  /** How long to wait when determining that a thread is blocked if we expect it to be blocked. */
  private static final long EXPECTED_HANG_DELAY_MILLIS = 75;

  /**
   * How long to wait when determining that a thread is blocked if we DON'T expect it to be blocked.
   */
  private static final long UNEXPECTED_HANG_DELAY_MILLIS = 10000;

  /**

	}
}

// IsSet will return whether the singleton has been set.
func (s *Singleton[T]) IsSet() bool {
	select {
	case <-s.set:
		return true
	default:
		return false
	}
}

// Set the value and unblock all Get requests.
// This may only be called once, a second call will panic.
func (s *Singleton[T]) Set(v *T) {
	s.v = v
	close(s.set)

			// are provided, we will not return bucket metrics.
			if bmg, ok := h.metricsData.bucketMGMap[collectorPath]; ok {
				if len(buckets) == 0 {
					continue
				}
				unLocker := bmg.LockAndSetBuckets(buckets)
				defer unLocker()
			}
			gatherers = append(gatherers, gatherer)
		}
	}

	if len(gatherers) == 0 {
		return notFoundHandler
	}

  private static final long SMALL_TIMEOUT_MILLIS = 10;

  /** How long to wait when determining that a thread is blocked if we expect it to be blocked. */
  private static final long EXPECTED_HANG_DELAY_MILLIS = 75;

  /**
   * How long to wait when determining that a thread is blocked if we DON'T expect it to be blocked.
   */
  private static final long UNEXPECTED_HANG_DELAY_MILLIS = 10000;

  /**

    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    // after some period of time the runner thread should become blocked on the task because it is
    // waiting for the slow interrupting thread to complete Thread.interrupt
    awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

            throw new RejectedExecutionException();
          }
        };
    final SequentialExecutor executor = new SequentialExecutor(delegate);
    final ExecutorService blocked = Executors.newCachedThreadPool();
    Future<?> first =
        blocked.submit(
            new Runnable() {
              @Override
              public void run() {
                executor.execute(Runnables.doNothing());
              }

            if (mirror.getLayout() != null && !mirror.getLayout().isEmpty()) {
                repository.setLayout(original.getLayout());
            }

            repository.setBlocked(mirror.isBlocked());
        }
    }

    private void injectProxy(ProxySelector selector, List<ArtifactRepository> repositories) {
        if (repositories != null && selector != null) {

            effectiveRepository.setProxy(aliasedRepo.getProxy());

            effectiveRepository.setMirroredRepositories(mirroredRepos);

            effectiveRepository.setBlocked(aliasedRepo.isBlocked());

            effectiveRepositories.add(effectiveRepository);
        }

        return effectiveRepositories;
    }

            throw new RejectedExecutionException();
          }
        };
    final SequentialExecutor executor = new SequentialExecutor(delegate);
    final ExecutorService blocked = Executors.newCachedThreadPool();
    Future<?> first =
        blocked.submit(
            new Runnable() {
              @Override
              public void run() {
                executor.execute(Runnables.doNothing());
              }