    /**
     * @override Ext.rtl.layout.component.Dock
     * This override adds RTL support to Ext.layout.component.Dock.
     */
    Ext.define('Ext.rtl.layout.component.Dock', {
        override: 'Ext.layout.component.Dock',

        rtlPositions: {
            top: 'top',
            right: 'left',
            bottom: 'bottom',
            left: 'right'
        },

        getDockCls: function(dock) {
            // When in RTL mode it is necessary to reverse "left" and "right" css class names.
            // We have to do it this way (as opposed to using css overrides) because of the
            // !important border-width rules, e.g.:
            // .x-docked-left { border-right-width: 0 !important; }
            return 'docked-' +
                (this.owner.getHierarchyState().rtl ? this.rtlPositions[dock] : dock);
        }
    });