content: import React from 'react';
  import { render } from 'react-dom';
  import injectTapEventPlugin from 'react-tap-event-plugin';
  
  import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
  import AppBar from 'material-ui/AppBar';
  import IconButton from 'material-ui/IconButton';
  import NavigationExpandMore from 'material-ui/svg-icons/navigation/expand-more'
  
  injectTapEventPlugin();
  
  const App = () => (
      <MuiThemeProvider>
          <AppBar title="Welcome to Express!" iconElementRight={<IconButton><NavigationExpandMore /></IconButton> } />
      </MuiThemeProvider>
  );
  render(<App />, document.getElementById('app'));