protected void addContentBasedFactories(IStructuredModel structuredModel) {
    FactoryRegistry factoryRegistry = structuredModel.getFactoryRegistry();
    Assert
        .isNotNull(factoryRegistry,
            "Program Error: client caller must ensure model has factory registry"); //$NON-NLS-1$
    INodeAdapterFactory factory = null;
    factory = factoryRegistry.getFactoryFor(IJFaceNodeAdapter.class);
    if (factory == null) {
      factory = new JFaceNodeAdapterFactoryForHTML(
          IJFaceNodeAdapter.class, true);
      factoryRegistry.addFactory(factory);