/**
 * Extends standard "Error" object to support adding extra properties.
 */
export declare class ErrorExtended<T> extends Error {
    /**
     * Known extended source names.
     */
    static sources: {
        getNoCache: string;
        aadSso: string;
    };
    /**
     * The extended error source name.
     */
    extendedSource: string;
    /**
     * The extended content.
     */
    extended: T;
}