@Test(expected = IllegalArgumentException.class)
public void testUnsupportedOperation() {

    RESTWorkItemHandler handler = new RESTWorkItemHandler();
    WorkItemImpl workItem = new WorkItemImpl();
    workItem.setParameter("Url",
                          serverURL + "/xml/john");
    workItem.setParameter("Method",
                          "HEAD");
    WorkItemManager manager = new TestWorkItemManager();
    handler.executeWorkItem(workItem,
                            manager);
}