anchor.diff:        Following our example through, what we really want to do is transform
         the promise via another operation. In our case, this second operation
         is synchronous, but it might just as easilly have been an asynchronous
  -      operation. Fortunately, promises have a (fully standardised, see
  -      warning re jQuery) method for transforming promises and chaining
  -      operations.
  +      operation. Fortunately, promises have a (fully standardised,
  +      #[a(href="#jquery") except jQuery]) method for transforming promises
  +      and chaining operations.
       p.
         Put simply, #[code .then] is to #[code .done] as
         #[code .map] is to #[code .forEach]. To put that another way, use
  
positive.code: 
      p Promises are useful both in node.js and the browser
  
      h3 Browser
  
      p.
        Promises are currently only supported by a pretty small selection of browsers
  
negative.code:       :html
          <script src="https://www.promisejs.org/polyfills/promise-done-1.0.0.js"></script>
  
      h3#node Node.js
      
      p It's generally not seen as good practice to polyfill things in node.js. Instead, you're better off just requiring the library wherever you need it.
      
  