private static void AssertNChar(char?expected, char?actual, string provider)
        {
            if (expected != null)
            {
                if (expected == ' ' &&
                    (provider == ProviderName.MySql ||
                     provider == ProviderName.MySqlConnector ||
                     provider == TestProvName.MariaDB ||
                     provider == TestProvName.MySql55 ||
                     TestProvName.IsiSeries(provider) && !TestProvName.IsiSeriesDB2Connect(provider)
                     // after migration to 2.4.126 provider + SPS4, hana or provider started to trim spaces on insert for some reason
                     || provider.StartsWith(ProviderName.SapHana)))
                {
                    expected = '\0';
                }
            }

            Assert.AreEqual(expected, actual);
        }