text: const express = require('express');
  const graphqlHTTP = require('express-graphql');
  const { express: voyagerMiddleware } = require('graphql-voyager/middleware');
  const schema = require('../schema');
  
  const app = express();
  const PORT = 3001;
  
  app.use('/graphql', graphqlHTTP(() => ({ schema })));
  app.use('/voyager', voyagerMiddleware({
    endpointUrl: 'http://localhost:4000/graphql',
    displayOptions: {
      sortByAlphabet: true,
    },
  }));
  
  app.listen(PORT, function() {
    const port = this.address().port;
  
    console.log(`Started on http://localhost:${port}/voyager`);
  });
  