code: function updateMulti( viewer ) {
      updateOnce( viewer );
  
      // Request the next frame, unless we've been closed
      if ( viewer.isOpen() ) {
          viewer._updateRequestId = scheduleUpdate( viewer, updateMulti );
      } else {
          viewer._updateRequestId = false;
      }
  }
docs: ///////////////////////////////////////////////////////////////////////////// Page update routines ( aka Views - for future reference ) /////////////////////////////////////////////////////////////////////////////