@Override
  public Set<GatewayReceiver> getGatewayReceivers() {
    GatewayReceiver receiver = gatewayReceiver.get();
    if (receiver == null) {
      return emptySet();
    }
    return Collections.singleton(receiver);
  }
For use by unit tests to inject a mocked ccpTimer
geode-core/src/main/java/org/apache/geode/internal/cache/GemFireCacheImpl.java