export type Listener<E> = (event: E) => void;
export declare class Emitter<Events extends Record<string, unknown>> {
	private readonly listeners;
	on<K extends keyof Events>(key: K, fn: Listener<Events[K]>): () => void;
	off<K extends keyof Events>(key: K, fn: Listener<Events[K]>): void;
	emit<K extends keyof Events>(key: K, event: Events[K]): void;
	clear(): void;
}