public async Task Test_NorthernIrishBankHolidayIsNotReturned()
        {
            using (var client = new HttpClient())
            {
                var fetcher = new BankHolidayFetcher(client);

                var result = await fetcher.Fetch();

                Assert.DoesNotContain(12.July(2018), result);
            }
        }
        public async Task Test_EnglishBankHolidayIsReturned()
        {
            using (var client = new HttpClient())
            {
                var fetcher = new BankHolidayFetcher(client);

                var result = await fetcher.Fetch();

                Assert.Contains(25.December(2018), result);
            }
        }