export interface ReadonlyAsyncEmitter<EventMap> {
    on<K extends keyof EventMap>(type: K | '*', listener: (event: EventMap[K]) => void | Promise<void>, order?: number): this;
    once<K extends keyof EventMap>(type: K | '*', listener: (event: EventMap[K]) => void | Promise<void>, order?: number): this;
    off<K extends keyof EventMap>(type: K | '*', listener: (event: EventMap[K]) => void | Promise<void>): this;
}
export interface AsyncEmitter<EventMap> extends ReadonlyAsyncEmitter<EventMap> {
    emit<K extends keyof EventMap>(type: K, event: EventMap[K]): Promise<void>;
}