code: public Observable<SourceUploadDefinitionInner> getBuildSourceUploadUrlAsync(String resourceGroupName, String registryName) {
          return getBuildSourceUploadUrlWithServiceResponseAsync(resourceGroupName, registryName).map(new Func1<ServiceResponse<SourceUploadDefinitionInner>, SourceUploadDefinitionInner>() {
              @Override
              public SourceUploadDefinitionInner call(ServiceResponse<SourceUploadDefinitionInner> response) {
                  return response.body();
              }
          });
      }
docs: Get the upload location for the user to be able to upload the source.
  
  @param resourceGroupName The name of the resource group to which the container registry belongs.
  @param registryName The name of the container registry.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the SourceUploadDefinitionInner object