type EventMap = Record<string, any>;
type EventKey<T extends EventMap> = string & keyof T;
type EventReceiver<T> = (params: T) => void;
export declare class Emitter<T extends EventMap> {
    private listeners;
    on<K extends EventKey<T>>(eventName: K, fn: EventReceiver<T[K]>): void;
    off<K extends EventKey<T>>(eventName: K, fn: EventReceiver<T[K]>): void;
    emit<K extends EventKey<T>>(eventName: K, params: T[K]): void;
}
export {};