code: public void shuffleAndIndexInstances(Map<String, Applications> remoteRegionsRegistry,
              EurekaClientConfig clientConfig, InstanceRegionChecker instanceRegionChecker) {
          shuffleInstances(clientConfig.shouldFilterOnlyUpInstances(), true, remoteRegionsRegistry, clientConfig,
                  instanceRegionChecker);
      }
docs: Shuffles a whole region so that the instances will not always be returned
  in the same order.
  
  @param remoteRegionsRegistry
  the map of remote region names to their registries
  @param clientConfig
  the {@link EurekaClientConfig}, whose settings will be used to
  determine whether to filter to only UP instances
  @param instanceRegionChecker
  the instance region checker