nanos -= System.nanoTime() - now; // subtract the actual time we waited
          }
        }
      }
    }

    /**
     * Checks if the executor has been shut down and increments the running task count.
     *
     * @throws RejectedExecutionException if the executor has been previously shutdown
     */
    private void startTask() {
      synchronized (lock) {
        if (shutdown) {