text: import React, { Component } from "react";
  import ReactDOM from "react-dom";
  import { BrowserRouter, Link, Route, Switch } from "react-router-dom";
  import Main from "./Router";
  class Index extends Component {
      render() {
          return (
              <BrowserRouter>
                  <Route component={Main} />
              </BrowserRouter>
          );
      }
  }
  ReactDOM.render(<Index />, document.getElementById("index"));
  