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

    expect(context.getSession()).andReturn(session);
    Enumeration<String> keys = createMock(Enumeration.class);
    expect(context.getAttributeNamesInScope(PageContext.SESSION_SCOPE)).andReturn(keys);
    replay(context, session);
    assertEquals(keys, extractor.getKeys());
    verify(context, session);
}