code: private Map<String, OperationResult<ModelMetadataKey>> getChangedMetadataKeys(Map<String, ModelMetadataKey> keyMap){
          return this.getDirectoryServiceClient().getChangedMetadataKeys(keyMap);
      }
docs: Get the changed list for the MetadataKey from the server.
  
  @param keyMap
  the MetadataKey list.
  @return
  the ModelMetadataKey list that has been changed.