code: public Observable<Image> addImageUrlInputAsync(String listId, String contentType, BodyModelModel imageUrl, AddImageUrlInputOptionalParameter addImageUrlInputOptionalParameter) {
          return addImageUrlInputWithServiceResponseAsync(listId, contentType, imageUrl, addImageUrlInputOptionalParameter).map(new Func1<ServiceResponse<Image>, Image>() {
              @Override
              public Image call(ServiceResponse<Image> response) {
                  return response.body();
              }
          });
      }
docs: Add an image to the list with list Id equal to list Id passed.
  
  @param listId List Id of the image list.
  @param contentType The content type.
  @param imageUrl The image url.
  @param addImageUrlInputOptionalParameter 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