export declare abstract class StorageService {
    abstract setItem: (key: string, value: string) => Promise<void>;
    abstract getItem: (key: string) => Promise<string | null>;
    setJSON: (key: string, jsonObj: object) => Promise<void>;
    getJSON: (key: string) => Promise<object | null>;
}
export declare class LocalStorage extends StorageService {
    private storage;
    constructor();
    setItem: (key: string, value: string) => Promise<void>;
    getItem: (key: string) => Promise<string | null>;
}