var Ancestor = function (){};
Ancestor.prototype.x = function (a){};
var Descendant = new Ancestor();
Descendant.prototype.y = function (b){};

var Ancestor = Function.create({
	constructor: function (){},
	x: function (a){}
});

var Descendant = Ancestor.extend({
	y: function (b){}
});

var Ancestor = new Class({
	initialize: function (){},
	x: function (a){}
});

var Descendant = new Class({
	Extends: Ancestor,
	y: function (b){}
});

var Ancestor = Ext.extend(Object, {
	constructor: function (){},
	x: function (a){}
});

var Descendant = Ext.extend(Ancestor, {
	y: function (b){}
});

var Ancestor = Class.create({
	initialize: function (){},
	x: function (a){}
});

var Descendant = Class.create(Ancestor, {
	y: function (b){}
});