[monolithed]

var foo = function (param) {
      this.property = param;

};

foo.prototype = {
      constructor: foo,
      method: function () {
             return this.property;
      }
}; 

var object = new foo (2);
alert(object.method()); // 2

object.constructor.prototype.method_2 = function() {
       return this.property * 2;
};

var object_2 = new foo(3);
alert([
   object.method_2(),    // 4
   object_2.method_2(),  // 6
   new foo(3).method_2() // 6
]);