code: public Observable<ServiceResponse<Image>> addImageWithServiceResponseAsync(String listId, AddImageOptionalParameter addImageOptionalParameter) {
          if (this.client.baseUrl() == null) {
              throw new IllegalArgumentException("Parameter this.client.baseUrl() is required and cannot be null.");
          }
          if (listId == null) {
              throw new IllegalArgumentException("Parameter listId is required and cannot be null.");
          }
          final Integer tag = addImageOptionalParameter != null ? addImageOptionalParameter.tag() : null;
          final String label = addImageOptionalParameter != null ? addImageOptionalParameter.label() : null;
  
          return addImageWithServiceResponseAsync(listId, tag, label);
      }
docs: Add an image to the list with list Id equal to list Id passed.
  
  @param listId List Id of the image list.
  @param addImageOptionalParameter the object representing the optional parameters to be set before calling this API
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the Image object