- http://justinfagnani.com/2015/12/21/real-mixins-with-javascript-classes/
- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes#Mix-ins
A mixin is an abstract subclass; i.e. a subclass definition that may be applied to different superclasses to create a related family of modified classes.
Gilad Bracha and William Cook, Mixin-based Inheritance
- mixin definition: The definition of a class that may be applied to different superclasses.