import { StorageAdapterClass, ValueStorageInterface } from './lib/interfaces';
declare type VisitorData = {
    [key: string]: string | number;
};
export declare class Visitor implements ValueStorageInterface {
    #private;
    protected data: VisitorData;
    private readonly storage;
    private readonly key;
    constructor(key: string, adapter: StorageAdapterClass, expiresInDays?: number);
    onUpdate(handler: (key: string, value: string) => void): void;
    getValue(key: string): any;
    setValue(key: string, value: any): void;
    setValueOnce(key: string, value: any): void;
    removeValue(key: string): void;
    now(): number;
    clear(): void;
    private save;
    private load;
}
export {};
//# sourceMappingURL=visitor.d.ts.map