* @return A source for reading the ZIP patch file for the described
* artifact and its update version.
*/
public Source diff(final ArtifactDescriptor descriptor,
final String updateVersion) {
return new Source() {
@Override public InputStream input() throws IOException {
return get(path("artifact/diff")
.queryParams(queryParameters(descriptor))
.queryParam("update-version", updateVersion)
.accept(APPLICATION_OCTET_STREAM_TYPE)