public void OrderExprParse()
        {
            var result = DslParser.OrderExprParse().Parse(@"order #alpha# asc, #beta# desc
select
select end");

            result.Should().NotBeNull();
            result.Items.Should().HaveCount(2);
            result.Items[0].OrderFieldName.Should().Be("alpha");
            result.Items[0].SortOrder.Should().Be(SortOrder.Ascending);

            result.Items[1].OrderFieldName.Should().Be("beta");
            result.Items[1].SortOrder.Should().Be(SortOrder.Descending);
        }