anchor.diff:              h3 Expression bodies
   
         section
  -        h1 Arrow functions
  -        pre
  -          code.language-javascript.
  -            
  +        h2 Arrow functions - Expression bodies
  +        pre
  +          code.language-javascript.
  +            // ES5
  +            let a = array.map(function(x) {
  +              return x * x;
  +            });
  +            // arrow function with expression body
  +            let b = array.map(x => x * x);
  +            // equivalent to
  +            let c = array.map(x => { return x * x; });
  +
  +      section
  +        h1.bullet Arrow functions - Gotchas
  +        ul
  +          li
  +            h3 Arrow functions do not have an arguments object
  +          li
  +            h3 To return an object wrap it in parentheses
  +          li
  +            pre
  +              code.language-javascript.
  +                var a = () => ({ x: 1 });
   
         section(data-bespoke-hash="modules")
           h1 Modules
  
positive.code:         h3.bullet Babel is built on plugins, different plugins for each feature
          ul.bigger-list
            li Features can be enabled by stage
            li Or selected language features individually
  
        section
          h1 ES2015 Features
  
negative.code:             }
  
        section
          h2 Poorly bound this
          pre
            code.language-javascript.
              function($rootScope) {
  