如何在kendo treelist中添加新标题？

Question

How to add a new header in the top of kendo treelist, like it is done in this picture:

I have tried

$("#treelist th.k-header").before('<tr><th>Stuff</th></tr>');

but it doesn't work......

My source:

    var dataSource = new kendo.data.TreeListDataSource({
        data: [
                { Id: 1, Name: "EASG", YQ: "150,000,000", M1: "1,000", M2: "1,000", M3: "1,000", MT: "5,000", MR: "50%", parentId: null },
                { Id: 2, Name: "MASD", YQ: "150,000,000", M1: "1,000", M2: "1,000", M3: "1,000", MT: "5,000", MR: "50%", parentId: 1 },
                { Id: 3, Name: "MASD_SD1", YQ: "150,000,000", M1: "1,000", M2: "1,000", M3: "1,000", MT: "5,000", MR: "50%", parentId: 2 },
                { Id: 4, Name: "New Biz", YQ: "150,000,000", M1: "1,000", M2: "1,000", M3: "1,000", MT: "5,000", MR: "50%", parentId: 3 },
                { Id: 8, Name: "FBU", YQ: "150,000,000", M1: "156,000", M2: "177,000", M3: "1,000", MT: "577,000", MR: "50%", parentId: 1 },
                { Id: 9, Name: "FBU_1", YQ: "150,000,000", M1: "156,000", M2: "177,000", M3: "1,000", MT: "577,000", MR: "50%", parentId: 8 }
        ],
        schema: {
            model: {
                id: "Id",
            }
        }
    });

    $("#treelist").kendoTreeList({
        dataSource: dataSource,
        columns: [
                  { field: "Name", title: "部門" },
                  { field: "YQ", title: "Yearly Quota" },
                  { field: "M1", title: "1月" },
                  { field: "M2", title: "2月" },
                  { field: "M3", title: "3月" },
                  { field: "MT", title: "合計" },
                  { field: "MR", title: "合計" }
        ]
    });

Answer 1

https://d585tldpucybw.cloudfront.net/forums/treelist-multi-column-headers

It seems not available.................