var Location_ = {ext: "loc"}
var Document_ = {}
Document_.__proto__.Location_ = Object.create(Location_.__proto__);
Document.__proto__.Location_.ext = 'doc';
var Page_ = Object.create(Document_.__proto__);
Page_.Location_.ext = 'page';
var Page2_ = Object.create(Document_.__proto__);
console.log(Location_.ext, Document_.Location_.ext, Page_.Location_.ext, Page2_.Location_.ext);
//loc page page page
var Page = Object.create(Document);
Page.Location = {ext:'loc'};
или var Page = Object.create(Document, {Location:{value:{ext:'loc'}}})