type EventName = string;
declare class Emitter {
    private e;
    private generateCallbackId;
    on(name: EventName, callback: () => void, ctx?: any): () => this;
    once(name: string, // EventName inlined as string
    callback: (...args: any[]) => void, ctx?: any): () => this;
    emit(name: EventName, ...data: any[]): this;
    off(name: EventName, callbackOrId?: (() => void) | string, ctx?: any): this;
}
export default Emitter;