seenExceptionsUpdater.compareAndSet(state, expect, update);
    }

    @Override
    int decrementAndGetRemainingCount(AggregateFutureState<?> state) {
      return remainingCountUpdater.decrementAndGet(state);
    }

    @Override
    String atomicHelperTypeForTest() {
      return "SafeAtomicHelper";
    }
  }

  private static final class SynchronizedAtomicHelper extends AtomicHelper {

    return addAndGet(key, 1);
  }

  /**
   * Decrements by one the value currently associated with {@code key}, and returns the new value.
   */
  @CanIgnoreReturnValue
  public long decrementAndGet(K key) {
    return addAndGet(key, -1);
  }

  /**
   * Adds {@code delta} to the value currently associated with {@code key}, and returns the new
   * value.
   */
  @CanIgnoreReturnValue

         * Decrements the reference count for this statistics object.
         *
         * @return the new reference count after decrementing
         */
        public int decrement() {
            return count.decrementAndGet();
        }
    }

    /**
     * Enumeration of predefined statistics actions that can be recorded
     * during crawler operations. Each action represents a specific event

    removeFromReplica(replica, replicatedMaxValue);
  }

  private static void removeFromReplica(Map<Integer, AtomicInteger> replica, int value) {
    AtomicInteger numOccur = replica.get(value);
    if (numOccur.decrementAndGet() == 0) {
      replica.remove(value);
    }
  }

  private static void assertIntact(MinMaxPriorityQueue<?> q) {
    if (!q.isIntact()) {
      fail("State " + Arrays.toString(q.toArray()));
    }

      delegateIndex = delegates.size();
    }

    @SuppressWarnings("Interruption") // We are propagating an interrupt from a caller.
    private void recordCompletion() {
      if (incompleteOutputCount.decrementAndGet() == 0 && wasCancelled) {
        for (ListenableFuture<? extends T> toCancel : inputFutures) {
          if (toCancel != null) {
            toCancel.cancel(shouldInterrupt);
          }
        }
      }