public void GuardForNullOrWhiteSpaceMustNotThorwArgumentNullExceptionWhenTheStringHasValue()
        {
            var @string   = "Is not null.";
            var exception = Record.Exception(()
                                             => StringGuard.ForNullOrWhiteSpace(@string, nameof(@string)));

            Assert.Null(exception);
        }
        public void GuardForNullOrWhiteSpaceMustThorwArgumentNullExceptionWhenTheStringIsNull()
        {
            string? @string  = null;
            Type    expected = GetArgumentNullExceptionType();

            Assert.Throws(expected, () =>
                          StringGuard.ForNullOrWhiteSpace(@string, nameof(@string)));
        }