@Test
public void testShouldFailWithoutSignature() throws Exception {

  RewardedAdsVerifier verifier =
      new RewardedAdsVerifier.Builder()
          .setVerifyingPublicKeys(GOOGLE_VERIFYING_PUBLIC_KEYS_JSON)
          .build();
  try {
    verifier.verify(REWARD_URL);
  } catch (GeneralSecurityException e) {
    assertEquals("signature and key id must be the last two query parameters", e.getMessage());
  }
}