@Test
public void shouldReturnOneAuthenticationWithGSSAPI() {

    Settings settings = Settings.builder()
            .put(AUTHENTICATION_SOURCE.get(), "database")
            .put(PASSWORD.get(), "password")
            .put(USER.get(), "user")
            .put(AUTHENTICATION_MECHANISM.get(), "GSSAPI")
            .build();
    MongoCredential credential = MongoAuthentication.of(settings).get();
    assertEquals("$external", credential.getSource());
    assertEquals("user", credential.getUserName());
    assertEquals(GSSAPI.getMechanismName(), credential.getMechanism());
}