text: const { ApolloServer, gql } = require('apollo-server');
  const SessionsAPI = require('./datasources/sessions');
  const SpeakersAPI = require('./datasources/speakers');
  const typeDefs = require('./schema');
  const resolvers = require('./resolvers');
  
  const dataSources = () => ({
    sessionsAPI: new SessionsAPI(),
    speakersAPI: new SpeakersAPI(),
  });
  
  const server = new ApolloServer({
    typeDefs,
    resolvers,
    dataSources
  });
  
  server.listen({ port: process.env.PORT || 4000 }).then(({ url }) => {
    console.log(`graphql running at ${url}`);
  });
  