/**
 * Represents the session state with expiration and last check timestamps.
 *
 * @category SDK
 * @subcategory Internal
 */
export interface State {
    expiration: number;
    lastCheck: number;
}
/**
 * Manages session state persistence using localStorage.
 *
 * @category SDK
 * @subcategory Internal
 */
export declare class SessionState {
    private readonly storageKey;
    private readonly defaultState;
    /**
     * Creates an instance of SessionState.
     *
     * @param {string} storageKey - The key used to store session state in localStorage.
     */
    constructor(storageKey: string);
    /**
     * Loads the current session state from localStorage.
     *
     * @returns {State} The parsed session state or a default state if not found.
     */
    load(): State;
    /**
     * Saves the session state to localStorage.
     *
     * @param {State | null} session - The session state to save. If null, the default state is used.
     */
    save(session: State | null): void;
}