if(!Object.prototype.size) {
	Object.prototype.size = function() {
		return Object.keys(this).length;
	}
}

if(!Object.prototype.size) {
	Object.defineProperty(Object.prototype, 'size', {
		enumerable:	false,
		configurable:	false,
		writable:		false,
		value: function() {
			return Object.keys(this).length;
		}
	});
}

if(!Object.prototype.size) {
	Object.defineProperty(Object.prototype, 'size', {
		value: function() {
			return Object.keys(this).length;
		}
	});
}

var arr = new Array(5);
arr[0] = 0;
arr[3] = 3;
arr.forEach(function(){
	console.log('each', arguments);
});

var arr = new Array(5);
arr.forEach(function(){
	console.log('each', arguments);
});

User.prototype.getGamePoints = function() {
	var persis = this.getPersistence();
	return persis.getNumber("points",0);
}

User.prototype.myPersis = null;
User.prototype.getMyPersistence = function() {
	if(this.myPersis == null)
		this.myPersis = this.getPersistence();
	return this.myPersis;
}

User.prototype.getGamePoints = function() {
	var persis = this.getMyPersistence();
	return persis.getNumber("points",0);
}

Card.Rarity = Object.freeze({
    COMMON: 0,
    UNCOMMON: 1,
    RARE: 2,
    LEGENDARY: 3
});

var abc = 'write/read';
const = def = 'read_only';

const abc = { a: 1, b:2 } >>>> Object {a: 1, b: 2}
abc.a = 3 >>> Object {a: 3, b: 2}
abc.d = 1 >>> Object {a: 3, b: 2, d: 1}

const abc = { a: 1, b:2 } >>>> Object {a: 1, b: 2}
abc = 'Foo'; >>>> code breaks