declare class FetchHelper {
    storagePrefix: string;
    constructor(namespace?: string);
    fetchJson(input: RequestInfo, init?: RequestInit, useCache?: boolean, onCacheUpdated?: Function): Promise<any>;
    wrapJson(data: any, permanent?: boolean): {
        timestamp: number;
        time: string;
        data: any;
        permanent: boolean;
    };
    store: {
        get: (key: string, permanentStorageFirst?: boolean) => any;
        set: (key: string, value: any, permanent?: boolean) => void;
        remove: (key: string) => void;
    };
}
export { FetchHelper };
