@Override
  public void endpointNoLongerInUse(Endpoint endpoint) {
    int count = endpointCount.decrementAndGet();
    if (logger.isDebugEnabled()) {
      logger.debug("PdxRegistryRecoveryListener - EndpointNoLongerInUse. Now have {} endpoints",
          count);
    }
  }
A listener which will wipe out the PDX registry on the client side if the entire server
distributed system was lost and came back on line. <br>
<br>
TODO - There is a window in which all of the servers could crash and come back up and we would
connect to a new server before realizing that all the servers crashed. To fix this, we would need
to get some kind of birthdate of the server ds we connect and use that to decide if we need to
recover the PDX registry.

We can also lose connectivity with the servers, even if the servers are still running. Maybe for
the PDX registry we need some way of telling if the PDX registry was lost at the server side in
the interval.
geode-core/src/main/java/org/apache/geode/cache/client/internal/PdxRegistryRecoveryListener.java