code: function assemble( page ) {
        if( typeof page !== 'object' ) {
           return Promise.reject( new Error(
              'PageAssembler.assemble must be called with a page artifact (object)'
           ) );
        }
        removeDisabledItems( page );
        return loadPageRecursively( page, page.name, [] );
     }
docs: Loads a page specification and resolves all extension and compositions. The result is a page were all
  referenced page fragments are merged in to one JavaScript object. Returns a promise that is either
  resolved with the constructed page or rejected with a JavaScript `Error` instance.
  
  @param {String} page
  the page to load. Usually a path relative to the base url, with the `.json` suffix omitted
  
  @return {Promise}
  the result promise