import { SubscriptionHistoryModel } from '../models/subscription';
export declare const ensureDiscount: ({ subscriptionBefore, subscriptionAfter }: SubscriptionHistoryModel) => boolean;
export declare const findFutureEvent: (history: SubscriptionHistoryModel[] | undefined, eventType: string) => SubscriptionHistoryModel | undefined;
export declare const isEventDateAfter: (subscriptionBefore: SubscriptionHistoryModel, subscriptionAfter: SubscriptionHistoryModel) => boolean;
export declare const findEvent: (history: SubscriptionHistoryModel[] | undefined, eventType: string) => SubscriptionHistoryModel | undefined;