private <T> Map getDefaultSettings(ElasticsearchPersistentEntity<T> persistentEntity) {
   return new MapBuilder<String, String>()
       .put("index.number_of_shards", String.valueOf(persistentEntity.getShards()))
       .put("index.number_of_replicas", String.valueOf(persistentEntity.getReplicas()))
       .put("index.refresh_interval", persistentEntity.getRefreshInterval())
       .put("index.store.type", persistentEntity.getIndexStoreType())
       .map();
 }