text: import React from 'react';
  import { BrowserRouter as Router, Switch, Route } from 'react-router-dom';
  import SearchBooks from './pages/SearchBooks';
  import SavedBooks from './pages/SavedBooks';
  import Navbar from './components/Navbar';
  import { ApolloProvider, ApolloClient, InMemoryCache, createHttpLink } from '@apollo/client';
  import { setContext } from '@apollo/client/link/context';
  
  const httpLink = createHttpLink({
    uri: '/graphql',
  });
  
  const authLink = setContext((_, { headers }) => {
    const token = localStorage.getItem('id_token');
    return {
      headers: {
        ...headers,
        authorization: token ? `Bearer ${token}` : '',
      },
    };
  });
  
  const client = new ApolloClient({
    link: authLink.concat(httpLink),
    cache: new InMemoryCache(),
  });
  
  function App() {
    return (
      <ApolloProvider client={client}>
        <Router>
          <>
            <Navbar />
            <Switch>
              <Route exact path="/" component={SearchBooks} />
              <Route exact path="/saved" component={SavedBooks} />
              <Route render={() => <h1 className="display-2">Wrong page!</h1>} />
            </Switch>
          </>
        </Router>
      </ApolloProvider>
    );
  };
  
  export default App;
  