code: public ServiceFuture<OperationStatus> deleteUnlabelledUtteranceAsync(UUID appId, String versionId, String utterance, final ServiceCallback<OperationStatus> serviceCallback) {
          return ServiceFuture.fromResponse(deleteUnlabelledUtteranceWithServiceResponseAsync(appId, versionId, utterance), serviceCallback);
      }
docs: Deleted an unlabelled utterance.
  
  @param appId The application ID.
  @param versionId The version ID.
  @param utterance The utterance text to delete.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object