public CompletableFuture<Void> allOfStartupTasks() {
    synchronized (startupTasks) {
      CompletableFuture<?>[] completableFutures = startupTasks.toArray(new CompletableFuture[0]);
      startupTasks.clear();
      return CompletableFuture.allOf(completableFutures);
    }
  }
Clears the startup tasks and returns a CompletableFuture that completes when all of the startup
tasks complete.

@return a CompletableFuture that completes when all of the startup tasks complete
geode-core/src/main/java/org/apache/geode/internal/cache/control/InternalResourceManager.java