    /**
     * Private utility class for Ext.layout.container.Border.
     * @private
     */
    Ext.define('Ext.resizer.BorderSplitter', {
        extend: 'Ext.resizer.Splitter',

        uses: ['Ext.resizer.BorderSplitterTracker'],

        alias: 'widget.bordersplitter',

        // must be configured in by the border layout:
        collapseTarget: null,

        getTrackerConfig: function () {
            var trackerConfig = this.callParent();

            trackerConfig.xclass = 'Ext.resizer.BorderSplitterTracker';

            return trackerConfig;
        }
    });