title: ES 6 Classes - Mixins
body: <p>I'm coming up with View (HTML markup) and Utility (JavaScript - behavior) architecture and creating atomic classes for composing views and utilities using ES6 Class. There will be a need that multiple utility classes can be composed/mixed into a single view class.</p>
  
  <p>How can ES6 Class API provide a way to mix-in class(es) into another/main class.  I've looked at <code>Object.assign</code> but that is for objects and not at class-level.</p>