}

  final Set<Throwable> getOrInitSeenExceptions() {
    if (seenExceptions == null) {
      seenExceptions = newHashSet();
      addInitialException(seenExceptions);
    }
    return seenExceptions;
  }

  abstract void addInitialException(Set<Throwable> seen);

  final int decrementRemainingAndGet() {
    return --remaining;
  }

  final void clearSeenExceptions() {

       * it with the initial failure before we do, or else they may think that the initial failure
       * has never been seen before.
       */
      addInitialException(seenExceptionsLocal);

      ATOMIC_HELPER.compareAndSetSeenExceptions(this, null, seenExceptionsLocal);
      /*
       * If another handleException() caller created the set, we need to use that copy in case yet

       * it with the initial failure before we do, or else they may think that the initial failure
       * has never been seen before.
       */
      addInitialException(seenExceptionsLocal);

      ATOMIC_HELPER.compareAndSetSeenExceptions(this, null, seenExceptionsLocal);
      /*
       * If another handleException() caller created the set, we need to use that copy in case yet