Configure datatable column header through HTML markup (for filter)

There are clear examples to configure datatable with columns through HTML markup. But I couldn’t figure out how to configure column header. For example, set building filter or have two row column header.
Thanks,
Tong

It is possible, but it will not look nice. You can use JSON in the HTML attributes

value='json://["Line1","Line2"]'

http://webix.com/snippet/066115c6