/** Asks `question` with ` [y/N] ` after it. Only `y` or `yes`, in any case,
 *  is a yes. `output` is where the question is written. A command whose
 *  standard output must hold only its result, such as
 *  `agency workflow run --json`, passes stderr. */
export declare function confirmQuestion(question: string, output?: NodeJS.WritableStream): Promise<boolean>;