@SuppressWarnings("unchecked")
@Test
public void testGetKeys() {

    Enumeration<String> keys = createMock(Enumeration.class);
    expect(request.getSession(false)).andReturn(session);
    expect(session.getAttributeNames()).andReturn(keys);
    replay(request, session, keys);
    assertEquals(keys, extractor.getKeys());
    verify(request, session, keys);
}