@VisibleForTesting
  public void setSendClientReadyInTestOnly() {
    synchronized (lock) {
      sentClientReady = true;
    }
  }
Manages Client Queues. Responsible for creating callback connections and satisfying redundancy
requirements.

@since GemFire 5.7
geode-core/src/main/java/org/apache/geode/cache/client/internal/QueueManagerImpl.java