private int initialThreadCountPlusAwaitility() {
    return initialThreads.size() + AWAITILITY_USAGE_THREAD_COUNT;
  }
Using Awaitility will increase total thread count by 1: ConditionAwaiter$ConditionPoller.
geode-core/src/integrationTest/java/org/apache/geode/distributed/LocatorLauncherJmxManagerLocalRegressionTest.java