element ui table total item merge

As shown in the picture:

code:

<el-table height="400px" :data="tableData " border
                      style="width: 100%"
                      stripe 
                      show-summary
                      ref="table"
                      id="table">
</el-table>

Listening form

watch: {
//监听table这个对象
        tableData: {
            // 立即监听
            immediate: true,
            handler() {
                this.$nextTick(() => {
                    const tds = document.querySelectorAll(
                        "#table .el-table__footer-wrapper tr>td"
                    );
                    // colSpan合并列
                    tds[0].colSpan = 2;
                    tds[0].style.textAlign = "center";
                    tds[1].style.display = "none";
                });
            },
        },
    },

I have merged the two items here, and the official one has not merged them.