createApolloServer = ({
  apolloServerOptions = {}, // apollo options
  config, // Vulcan options
}) => {
  // given options contains the schema
  const apolloServer = new ApolloServer({
    // graphql playground (replacement to graphiql), available on the app path
    playground: getPlaygroundConfig(config),
    // context optionbject or a function of the current request (+ maybe some other params)
    debug: Meteor.isDevelopment,
    cache: 'bounded',
    ...apolloServerOptions,
  });

  // default function does nothing
  if (config.configServer) {
    config.configServer(apolloServer);
  }

  return apolloServer;
}
Options: Apollo server usual options
Config: a config specific to Vulcan