export declare class Cache<Key, T> {
    private onDelete?;
    cache: Map<Key, T>;
    constructor(onDelete?: ((item?: T) => void) | undefined);
    get(key: Key): T | undefined;
    add(key: Key, data: T): void;
    patch(key: Key, data: T): void;
    delete(key: Key): void;
    clear(): void;
}