@VisibleForTesting
  Map<ClientProxyMembershipID, Long> getClientHeartbeats() {
    return clientHeartbeats.entrySet().stream()
        .collect(Collectors.toMap(Map.Entry::getKey, entry -> entry.getValue().get()));
  }
Returns the map of known clients.

@return the map of known clients

        Test hook only.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ClientHealthMonitor.java