anchor.diff:  = Promises API Reference
   
   [[promise.then]]
  +== promise.then
   [source,js]
   ----
   promise.then(<onFulfilled>, <onRejected>);
  
positive.code: `promise.then(undefined, onRejected)` と同等の意味を持つシンタックスシュガー。
  
  [[Promise.resolve]]
  [source,js]
  ----
  Promise.resolve(promise);
  
negative.code: 
  
  [[Promise.all]]
  == Promise.all
  [source,js]
  Promise.all(promiseArray);
  
  