public ClassDescriptor buildRootDescriptor() {
    XMLDescriptor descriptor = new XMLDescriptor();
    descriptor.setJavaClass(Root.class);
    descriptor.setDefaultRootElement("root");

    XMLAnyCollectionMapping mapping = new XMLAnyCollectionMapping();
    mapping.setAttributeName("any");
    mapping.setGetMethodName("getAny");
    mapping.setSetMethodName("setAny");
    mapping.setKeepAsElementPolicy(UnmarshalKeepAsElementPolicy.KEEP_UNKNOWN_AS_ELEMENT);
    descriptor.addMapping(mapping);

    return descriptor;
  }