type CallbackFn = (data: any) => void;
declare class EventBus {
    private events;
    on(event: string, callback: CallbackFn): void;
    once(event: string, callback: CallbackFn): void;
    emit(event: string, data?: any): void;
    off(event: string, callback?: CallbackFn): void;
}
declare const _default: EventBus;
export default _default;