void clearPdxRegistry(Endpoint endpoint) {
      for (EndpointListener listener : endpointListeners) {
        if (listener instanceof PdxRegistryRecoveryListener) {
          listener.endpointNowInUse(endpoint);
        }
      }
    }
Used by Endpoint only, when the reference count for this endpoint reaches 0
geode-core/src/main/java/org/apache/geode/cache/client/internal/EndpointManagerImpl.java