Factory pattern javascript

factory.js

// Constructor
var Class = function(value1, value2) {  }

// Factory
Class.factory(value1) { 
  return new Class(value1, 'aaa'); 
};

// properties and methods
Class.prototype = { ... };

// http://blog.mixu.net/2011/02/02/essential-node-js-patterns-and-snippets/