text: import React from 'react'
  import MainRouter from './MainRouter'
  import {BrowserRouter} from 'react-router-dom'
  import {ThemeProvider} from '@material-ui/styles'
  import theme from './theme'
  import { hot } from 'react-hot-loader'
  
  const App = () => {
    React.useEffect(() => {
      const jssStyles = document.querySelector('#jss-server-side')
      if (jssStyles) {
        jssStyles.parentNode.removeChild(jssStyles)
      }
    }, [])
    return (
      <BrowserRouter>
        <ThemeProvider theme={theme}>
          <MainRouter />
        </ThemeProvider>
      </BrowserRouter>
    )
  }
  
  export default hot(module) (App)
  