code: function updateAvailablePages(pages) {
          var i, page;
          for (i = 0; i < pages.length; ++i) {
              page = pages[i];
              viewerAPI.fire('realtimeupdate', { page: page });
              scope.broadcast('pageavailable', { page: page });
          }
      }
docs: Notify the viewer that new pages are available for loading
  @param   {Array} pages Array of integer page numbers that are available
  @returns {void}
  @private