//(function () {
    var Shape = (function () {

        function Shape(x, y, color) {
            this._x = x;
            this._y = y;
            this._color = color;
        }
        Shape.prototype.toString = function(){
                return "x= " + this._x, + ", y= " + this._y + "color: " + this._color;
        }
        return Shape;
    }());

    var Circle = (function () {

        function Circle(x, y, color, r) {
            Shape.call(this, x, y, color);
            this._r = r;
        }
        Circle.prototype = Object.create(Shape.prototype);
        Circle.prototype.constructor = Circle;
      //  Circle.prototype = new Shape();
        return Circle;

        Circle.prototype.toString = function () {
            return Shape.prototype.toString.call(this) + ", r = " + this._r;
        }
    }());

    var c = new Circle(1, 2, 5, 7);
    console.log(c.toString());
//}());