JS: Object.setPrototypeOf

New in ES2015.

Object.setPrototypeOf ( obj, proto )

Set the parent of obj to proto.

Return the changed obj.

let aa = {};
let bb = Object.create (aa);

// bb's parent is aa
console.log ( Object.getPrototypeOf ( bb ) === aa ); // true

// now change parent
let cc = Object.setPrototypeOf ( bb, Array );

// return value is the new bb
console.log ( cc === bb ); // true
console.log ( Object.getPrototypeOf ( bb ) === Array ); // true

[see JS: Prototype and Inheritance]

[see JS: Get/Set Prototype]

Reference

ECMAScript® 2016 Language Specification#sec-object.setprototypeof