export type EventIdentifier = string | symbol;
export type EventCallback = (event: any) => any;
export interface IEventListener {
    on(event: EventIdentifier, cb: EventCallback): void;
}
export interface IEventSubscriber {
    subscribe(listener: IEventListener): void;
}
export interface IEventHandler {
    subscriber(subscriber: IEventSubscriber): void;
    on(event: EventIdentifier, cb: EventCallback): void;
    emit(event: EventIdentifier, data: any): void;
}