@Test
public void validate_noAudienceInJwt_shouldThrow() throws Exception {

  ToBeSignedJwt unverified = new ToBeSignedJwt.Builder().setAlgorithm("HS256").build();
  JwtValidator validator = new JwtValidator.Builder().setAudience("foo").build();
  assertThrows(JwtInvalidException.class, () -> validator.validate("HS256", unverified));
}