@Test
public void testRemoveAttribute() {

  RepositoryBackedSession rbs = new RepositoryBackedSession(sessionData, manager, factory);
  rbs.setAttribute("Test", "value");
  rbs.removeAttribute("Test");
  verify(notifier).attributeRemoved(refEq(rbs), eq("Test"), eq("value"));
  assertNull(rbs.getAttribute("Test"));
}