@Test
public void testGetPeerAuthenticatorInstances() throws Exception {

  when(config.getPeerAuthenticators()).thenReturn(
      ImmutableList.of(PassPeerAuthenticator.class, FailPeerAuthenticator.class));
  List<PeerAuthenticator> peerAuthenticators =
      Lists.newArrayList(peerAuth.getPeerAuthenticatorInstances());
  assertEquals(2, peerAuthenticators.size());
  assertTrue(peerAuthenticators.get(0) instanceof PassPeerAuthenticator);
  assertTrue(peerAuthenticators.get(1) instanceof FailPeerAuthenticator);
}