JavaScript: Class simulation

gistfile1.js

/// Make this script available somewhere
var extendsClass = this.extendsClass || function (d, b) {
    function __inheritedProto() { this.constructor = d; }
    __inheritedProto.prototype = b.prototype;
    d.prototype = new __inheritedProto();
}

/// Sample class 1
var CLASS = (function() {
    function CLASS(data) {
        this.value = data;
    }
    CLASS.prototype.method = function() {
        return this.value;
    };
    return CLASS;
})();

/// Sample class 2, extends class 1
var CLASS2 = (function(_super) {
    extendsClass(CLASS2, _super);
    function CLASS2() {
        _super.apply(this, arguments);
    }
    CLASS2.prototype.method2 = function() {
        return this.value * 2; //do something else
    };
    return CLASS2;
})(CLASS);

/// Create some instances
var instance = new CLASS(1);
var instance2 = new CLASS2(2);


/// Call some methods
instance.method();  // 1
instance2.method(); // 2
instance2.method2();// 4