el-table中的span-method
```javascript
<el-table
:span-method="arraySpanMethod"
// ...
/>
```
<!--more-->
```javascript
arraySpanMethod({ row, column, rowIndex, columnIndex }) {
const { nodeNum, count, nodeName, nodeRemark } = row
if ([0, 1].includes(columnIndex)) { // 只合并第一列和第二列
switch
more...



