public SortDescriptor <T> Descending(SortSpecialField field) => Assign(a => a.Add(new SortField { Field = field.GetStringValue(), Order = SortOrder.Descending }));
public SortDescriptor <T> Descending(SortSpecialField field) => Assign(field.GetStringValue(), (a, v) => a.Add(new FieldSort { Field = v, Order = SortOrder.Descending }));