NtlmPasswordAuthenticator ntlmGuestCreds = guestCreds.unwrap(NtlmPasswordAuthenticator.class);
        assertThat("anonymous", ntlmGuestCreds.isAnonymous(), CoreMatchers.is(false));
        assertThat("guest", ntlmGuestCreds.isGuest(), CoreMatchers.is(true));

        Credentials anonCreds = this.context.withAnonymousCredentials().getCredentials();
        assertThat(anonCreds, CoreMatchers.is(CoreMatchers.instanceOf(NtlmPasswordAuthenticator.class)));