NodeJS Native Addon: How to pass js object instance as argument to the native part?

Does it possible to pass javascript instantiated object to the (c++) native addon? For example consider following code snippet - the 'sum' function must be called within native addon ( within fn() ) and the result is returned back to JS part:

var addon = require('addon');

var JSClass = (function () {
    function JSClass(a, b) {
        this.a = a;
        this.b = b;
    }
    JSClass.prototype.sum = function () {
        return this.a + this.b;
    };
    return JSClass;
})();

var result = addon.fn(new JSClass(3, 5));
console.log("resulted sum = " + result);

I tried to adapt this example of passing wrapped object without success.