export declare class NCPersistance {
    private storage;
    constructor(isInstant?: boolean);
    put(key: string, value: string): void;
    get(key: string, defaultValue?: string | null): Promise<string | null>;
    delete(key: string): Promise<boolean>;
    putNumber(key: string, value: number): void;
    putObject<T>(key: string, value: T): void;
    getNumber(key: string, defaultValue?: number): number;
    getObject<T>(key: string): Promise<T | null>;
}