docs: private List<ModelMetadataKey> getAllMetadataKeysForSync(){
          List<ModelMetadataKey> allKeys = new ArrayList<ModelMetadataKey>();
          allKeys.addAll(this.metaKeyCache.values());
          List<ModelMetadataKey> syncKeys = new ArrayList<ModelMetadataKey>();
          for(ModelMetadataKey service : allKeys){
              ModelMetadataKey syncKey = new ModelMetadataKey(service.getName(), service.getId(), service.getModifiedTime(), service.getCreateTime());
              syncKeys.add(syncKey);
          }
          return syncKeys;
      }