declare namespace Ext {
    export namespace dom {
        export interface ShadowConfig {
            mode?: string;
            offset?: number;
            target?: Ext.dom.Element;
            zIndex?: number;
        }

        export class Shadow extends Ext.dom.Underlay  {
            public offsets?: object;
            public outerOffsets?: object;
            public constructor(config?: object);
            public setOpacity(opacity?: number): void;
        }
    }
}