Illumination of https://github.com/sinonjs/sinon/issues/1892#issuecomment-419755839

prototype session

$ node
> class A{ constructor(){ console.log('A normal super class'); } }
undefined
> class B extends A{}
undefined
> new B
A normal super class
B {}
> sinon = require('sinon')
    ...
> Object.setPrototypeOf(B, sinon.stub().callsFake(function() { console.log('I am Super Stub!'); } ))
[Function: B]
> new B
I am Super Stub!
B {}
> Object.getPrototypeOf(B).callCount
1
> new B && Object.getPrototypeOf(B).callCount
I am Super Stub!
2
> Object.getPrototypeOf(B) === B.__proto__
true


// now for some old school ES5 equivalents

> function C() { console.log('An old-skool super class'); }
undefined
> function D(){ C.call(this); }
undefined
> new D()
An old-skool super class
D {}
> D.prototype = Object.create(C.prototype)
C {}
> new D instanceof C
An old-skool super class
true