anchor.diff:              }
   
         section
  -        h1 Subclass
  +        h2 Subclass
           pre
             code.language-javascript.
               class Point3D extends Point {
  
positive.code:             }
  
        section
          h1 Arrow functions
          pre
            code.language-javascript.
              function($rootScope) {
  
negative.code:               h3 ES2015 #[span.token.keyword class] is mostly syntactic sugar on this design pattern
  
        section
          h2 ES5 Class
          pre
            code.language-javascript.
              // constructor function
  