export type QueueEntryLimitReachedBehavior = 'enqueue' | 'throw' | 'null';
export interface QueueEntry<Req, Res, Err = Error> {
req: Req;
resolve: (res: Res | PromiseLike<Res>) => void;
reject: (err: Err) => void;
limitReachedBehavior: QueueEntryLimitReachedBehavior;
}