private void doRewriterTest(final Asset asset,
final AssetGroup assetGroup,
final MarinerURL marinerURL,
final String expected) throws Exception {
volantis = new TestableVolantis();
ServletContextStub servletContext = new ServletContextStub();
AppManager manager = new AppManager(volantis, servletContext);
manager.useAppWith(new AppExecutor() {
public void execute(AppContext context) throws Exception {
MyMarinerPageContext pageContext = new MyMarinerPageContext();