Interface EventBus<M>

interface EventBus<M> {
    emit<K extends string | number | symbol>(evt: K, payload: M[K]): boolean;
    off<K extends string | number | symbol>(
        evt: K,
        fn: (payload: M[K]) => void,
    ): void;
    on<K extends string | number | symbol>(
        evt: K,
        fn: (payload: M[K]) => void,
    ): Unsubscribe;
    once<K extends string | number | symbol>(
        evt: K,
        fn: (payload: M[K]) => void,
    ): Unsubscribe;
}