Functional Mixins in ECMAScript 2015

In Prototypes are Objects, we saw that you can emulate “mixins” using Object.assign on the prototypes that underly JavaScript “classes.” We’ll revisit this subject now and spend more time looking at mixing functionality into classes. First, a quick recap: In JavaScript, a “class” is implemented as a constructor function and its prototype, whether you write it directly, or use the class keyword. In