type EventMap = Record<string, any>;
type EventKey<KeyMap extends EventMap> = string & keyof KeyMap;
type EventReceiver<KeyMap> = (params: KeyMap) => void;
export interface Emitter<KeyMap extends EventMap> {
    on<Key extends EventKey<KeyMap>>(eventName: Key, fn: EventReceiver<KeyMap[Key]>): void;
    off<Key extends EventKey<KeyMap>>(eventName: Key, fn: EventReceiver<KeyMap[Key]>): void;
    emit<Key extends EventKey<KeyMap>>(eventName: Key, params: KeyMap[Key]): void;
}
export declare class EventEmitter<KeyMap extends EventMap> implements Emitter<KeyMap> {
    listeners: {
        [Key in keyof EventMap]?: ((p: EventMap[Key]) => void)[];
    };
    on<Key extends EventKey<KeyMap>>(eventName: Key, fn: EventReceiver<KeyMap[Key]>): void;
    off<Key extends EventKey<KeyMap>>(eventName: Key, fn: EventReceiver<KeyMap[Key]>): void;
    emit<Key extends EventKey<KeyMap>>(eventName: Key, data?: KeyMap[Key]): void;
}
export {};