import { ResourceState, LooseApi, Family } from './interface.js';
export declare class ObservableCache {
    private readonly cache;
    private readonly listeners;
    private version;
    constructor(cache: WeakMap<LooseApi, Family<unknown>>);
    getVersion(): number;
    init(api: LooseApi, key: string, promise: Promise<unknown>): void;
    set(api: LooseApi, key: string, value: ResourceState<unknown>): void;
    get(api: LooseApi, key: string): ResourceState<unknown> | undefined;
    has(api: LooseApi, key: string): boolean;
    observe(api: LooseApi, key: string, callback: () => void): () => void;
    private getFamilySafe;
    private notify;
}