@Test
public void testGetAuthenticatorInstances_nonSingleton() throws Exception {

  when(config.getAuthenticators()).thenReturn(ImmutableList.of(PassAuthenticator.class,
      FailAuthenticator.class, FailAuthenticator.class));
  List<Authenticator> authenticators = Lists.newArrayList(auth.getAuthenticatorInstances());
  assertEquals(3, authenticators.size());
  assertTrue(authenticators.get(0) instanceof PassAuthenticator);
  assertTrue(authenticators.get(1) instanceof FailAuthenticator);
  assertTrue(authenticators.get(2) instanceof FailAuthenticator);
  assertNotSame(authenticators.get(1), authenticators.get(2));
}