message: MockMslUser only accepts int64_t values for the serialized user data.
diff: @@ -213,7 +213,7 @@ TEST_F(MslExceptionTest, UserIdToken)
  shared_ptr<MslContext> ctx = make_shared<MockMslContext >(EntityAuthenticationScheme::PSK, false);
  shared_ptr<MasterToken> mt = MslTestUtils::getMasterToken(ctx, 1111, 2222);
  const int64_t serialNumber = 3333;
  - shared_ptr<MslUser> user = make_shared<NiceMock<MockMslUser>>("foo");
  + shared_ptr<MslUser> user = make_shared<NiceMock<MockMslUser>>("17");
  uit1 = MslTestUtils::getUserIdToken(ctx, mt, serialNumber, user);
  // set / get
  