how to achieve the effect of colspan and rowspan of table of ordinary html in Table component of iviewui?

the code is as follows:

<Table border :columns="columns" :data="list"></Table>


      columns: [
        { 
          title: " ",
          key: "",
          render: (h, params) => {
            return h("div", [
                h("Checkbox", {
                  props: {
                    label: params.row.name_1,
                  }
                },
                params.row.name_1)
              ]);
          }
        },
        { 
          title: " ",
          key: "",
          render: (h, params) => {
            return h("div", [
                h("Checkbox", {
                  props: {
                    label: params.row.name_2,
                  }
                },
                params.row.name_2)
              ]);
          }
        }
      ],
      
      
      list: [
        {
          name_1: 1,
          name_2: 1.1
        },
        {
          name_1: 1,
          name_2: 1.2
        },
        {
          name_1: 1,
          name_2: 1.3
        },
        {
          name_1: 2,
          name_2: 2.1
        },
        {
          name_1: 2,
          name_2: 2.2
        },
      ],

the effect now looks like this:

ordinary table tables can achieve the effect of juxtaposition and parallelism by setting colspan and rowspan.

but the Table component in iviewui, what can I do to merge the ones shown as 1 in the figure into one cell and the ones shown as 2 into one cell?