code: public Observable<GalleryImageInner> getAsync(String resourceGroupName, String labAccountName, String galleryImageName) {
          return getWithServiceResponseAsync(resourceGroupName, labAccountName, galleryImageName).map(new Func1<ServiceResponse<GalleryImageInner>, GalleryImageInner>() {
              @Override
              public GalleryImageInner call(ServiceResponse<GalleryImageInner> response) {
                  return response.body();
              }
          });
      }
docs: Get gallery image.
  
  @param resourceGroupName The name of the resource group.
  @param labAccountName The name of the lab Account.
  @param galleryImageName The name of the gallery Image.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the GalleryImageInner object