anchor.diff:  [source,javascript]
   ----
   function dummyFetch(path) {
  -    return new Promise((resolve, reject) => {
  -        setTimeout(() => {
  +    return new Promise(function(resolve, reject){
  +        setTimeout(function(){
               if (path.startsWith("/resource")) {
                   resolve({ body: `Response body of ${path}` });
               } else {
  
positive.code:         dummyFetch("/resource/A"),
          dummyFetch("/resource/B")
      ]);
      return responses.map(response => {
          return response.body;
      });
  }
  // リソースを取得して出力する
  fetchResources().then((results) => {
      console.log(results); // => ["Response body of /resource/A", "Response body of /resource/B"]
  });
  ----
  
negative.code: }
  const resources = ["/resource/A", "/resource/B"];
  // リソースを取得して出力する
  fetchResources(resources).then(function(results){
      console.log(results); // => ["Response body of /resource/A", "Response body of /resource/B"]
  });
  ----
  