title: Is there a way to create interfaces in ES6 / Node 4?
body: <p>ES6 is fully available in Node 4. I was wondering whether it includes a concept of interface to define method contracts as in <code>MyClass implements MyInterface</code>. </p>
  
  <p>I can't find much with my Googling, but maybe there is a nice trick or workaround available.</p>