After running the example I got errors

After installing the library in next.js, placing the global css in /pages/_app.js, the error you got was this:
```
export * from './common';
^^^^^^

SyntaxError: Unexpected token export
```
My code used:
```
import React, { Component } from 'react';
import SortableTree from 'react-sortable-tree';
// import 'react-sortable-tree/style.css'; // This only needs to be imported once in your app

export default class Tree extends Component {
constructor(props) {
super(props);

this.state = {
treeData: [
{ title: 'Chicken', children: [{ title: 'Egg' }] },
{ title: 'Fish', children: [{ title: 'fingerline'}] }
],
};
}

render() {
return (

Please help me solve this. I really want to use this library.

Reproduce the reported installation in a Next.js app with the global stylesheet imported from /pages/_app.js, then investigate the SyntaxError at './common'. Done means the provided tree example builds and runs without the unexpected export error.

Written by the indexing model from the issue text.