/**
 * Based on https://gist.github.com/nfantone/1eaa803772025df69d07f4dbf5df7e58.
 */
type BeforeShutdownListener = (codeOrSignal: string | number) => Promise<void> | void;
/**
 * Registers a new shutdown listener to be invoked before exiting
 * the main process. Listener handlers are guaranteed to be called in the order
 * they were registered.
 * @param listener The shutdown listener to register.
 * @returns Echoes back the supplied `listener`.
 */
export declare function beforeShutdown(listener: BeforeShutdownListener): BeforeShutdownListener;
export {};