public Set<Thread> getThreads() {
    return threadFactory.getThreads();
  }
Returns the {@code Thread}s that are directly in the {@code ExecutorService}'s
{@code ThreadGroup} excluding subgroups.

@return the {@code Thread}s that are directly in the {@code ExecutorService}'s
        {@code ThreadGroup} excluding subgroups
geode-junit/src/main/java/org/apache/geode/test/junit/rules/ExecutorServiceRule.java