This is a very tiny and simple data structure making use of some ECMAScript 2015 new features.
Inspired by James Kyle's itsy-bitsy-data-structures. I highly recommend you to read his first.
I learned all the new features of ES6 from Nicholas C. Zakas' book Understanding ECMAScript 6.
1, class and class inheritance.
2, Proxy and Reflection API
3, generator
Besides, in the code I showed a way to make some private javascript class members.
Hope you like it!