@Override
  public void before() {
    threadFactory = new DedicatedThreadFactory(threadNameFunction);
    if (threadCount > 0) {
      executor = Executors.newFixedThreadPool(threadCount, threadFactory);
    } else {
      executor = Executors.newCachedThreadPool(threadFactory);
    }
  }
Constructs a {@code ExecutorServiceRule} which invokes {@code ExecutorService.shutdownNow()}
during {@code tearDown}.

@param threadCount The number of threads in the pool. Creates fixed thread pool if &gt;; else
       creates cached thread pool.
geode-junit/src/main/java/org/apache/geode/test/junit/rules/ExecutorServiceRule.java