How to customize object equality for JavaScript Set

Question

New ES 6 (Harmony) introduces new Set object. Identity algorithm used by Set is similar to === operator and so not much suitable for comparing objects:

Answer 1

To someone who found this question on Google (as me) wanting to get a value of a Map using an object as Key:

Warning: this answer will not work with all objects

var map = new Map();

map.set(JSON.stringify({"A":2} /*string of object as key*/), "Worked");

console.log(map.get(JSON.stringify({"A":2}))||"Not worked");

Output:

Worked