Construct the "XWiki" JavaScript object using the module "loose augmentation" pattern

if (typeof XWiki == "undefined") {
   XWiki = new Object();
}

// XWiki module augmentation
XWiki.submodule = Class.create({
   //etc
});

var XWiki = (function(x) {

   // module augmentation :
   x.submodule = Class.create({
     //etc.
   });

   return x;

})(XWiki || {});