declare namespace Ext {
    export namespace resizer {
        export interface ResizeTrackerConfig {
            autoStart?: boolean | number;
            constrainTo?: Ext.util.Region | Ext.dom.Element;
            delegate?: string;
            el?: Ext.dom.Element | string;
            listeners?: object;
            overCls?: string;
            preventDefault?: boolean;
            stopEvent?: boolean;
            tolerance?: number;
            trackOver?: boolean;
        }

        export class ResizeTracker extends Ext.dd.DragTracker  {
            public createProxy(target?: Ext.Component | Ext.dom.Element): Ext.dom.Element;
        }
    }
}