public void CreateMethod()
        {
            // preparation
            var config = new Mock <IConfiguration>();

            config.Setup(_ => _["VerificationKeySecret"]).Returns(PrivateKey);
            var logger = new Mock.LoggerMock <TemporaryExposureKeySignService>();
            // action
            var service = new TemporaryExposureKeySignService(config.Object, logger);
        }