/** @returns Promise that will be resolved or rejected in `timeout` */
export declare function promisifyTimeout(timeout: number): Promise<undefined>;
/**
 * @returns Promise that will be resolved or rejected in `timeout` with an optional `payload`
 * If `isReject` is `true` the result promise will be rejected, otherwise (by default) the result promise will be resolved
 */
export declare function promisifyTimeout<T>(timeout: number, payload: T, isReject?: boolean): Promise<T>;