public void addStartupTask(CompletableFuture<Void> startupTask) {
    Objects.requireNonNull(startupTask);
    synchronized (startupTasks) {
      startupTasks.add(startupTask);
    }
  }
Adds a task that represents an asynchronous action during startup

@param startupTask the CompletableFuture startup task
geode-core/src/main/java/org/apache/geode/internal/cache/control/InternalResourceManager.java