fullyLoadedHandler =  function() {
            var newFullyLoaded = _this._areAllFullyLoaded();
            if (newFullyLoaded !== _this._fullyLoaded) {
                _this._fullyLoaded = newFullyLoaded;

                /**
                 * Fired when the viewer's aggregate "fully loaded" state changes (when all
                 * TiledImages in the world have loaded tiles for the current view resolution).
                 *
                 * @event fully-loaded-change
                 * @memberof OpenSeadragon.Viewer
                 * @type {object}
                 * @property {Boolean} fullyLoaded - The new aggregate "fully loaded" value
                 * @property {OpenSeadragon.Viewer} eventSource - Reference to the Viewer instance
                 * @property {?Object} userData - Arbitrary subscriber-defined object
                 */
                _this.raiseEvent('fully-loaded-change', {
                    fullyLoaded: newFullyLoaded
                });
            }
        }
@member {OpenSeadragon.Navigator} navigator
@memberof OpenSeadragon.Viewer#