export type Klass = new (...args: unknown[]) => unknown;
export interface KlassHelper {
    super_: typeof Function.prototype;
    superConstruct: () => Klass;
}
export interface Options {
    ensureProperties?: unknown[];
}
declare function extendLegacy(child_: unknown, parent_: unknown, options?: Options): void;
declare const _default: typeof extendLegacy;
export default _default;