export interface SingletonPromiseReturn<T> {
    (): Promise<T>;
    /**
     * Reset current staled promise.
     * await it to have proper shutdown.
     */
    reset: () => Promise<void>;
}
/**
 * Create singleton promise function
 *
 * @example
 * ```
 * const promise = createSingletonPromise(async () => { ... })
 *
 * await promise()
 * await promise() // all of them will be bind to a single promise instance
 * await promise() // and be resolved together
 * ```
 */
export default function createSingletonPromise<T>(fn: () => Promise<T>): SingletonPromiseReturn<T>;