@Test
  public void authenticateShouldReturnFailureMessageIfLoginThrows() throws Exception {
    when(securityService.login(any(Properties.class)))
        .thenThrow(new GemFireSecurityException("dummy"));
    props.setProperty(SECURITY_MANAGER, "dummy");
    String result = authenticator.authenticate(member, props, props);
    assertThat(result).startsWith("Security check failed. dummy");
  }
Unit tests GMSAuthenticator using new integrated security.
geode-core/src/test/java/org/apache/geode/distributed/internal/membership/adapter/auth/GMSAuthenticatorWithSecurityManagerTest.java