export declare class StorageService {
    /**
     * Sets a given value identified by a given key, in session storage.
     * The value will be stored as a JSON string.
     */
    sessionStorageSet(key: string, value: any): void;
    /**
     * Get a value from session storage, by a given key.
     * @returns The unserialised object if found, otherwise the provided default value.
     *          If no default value is provided, it returns `null`.
     */
    sessionStorageGet<T>(key: string, defaultValue?: T): T | null;
    /**
     * Sets a given value identified by a given key, as a session cookie.
     * The value will be stored as a JSON string.
     */
    sessionCookieSet(key: string, value: any): void;
    /**
     * Get a value from session cookies, by a given key.
     * @returns The unserialised object if found, otherwise the provided default value.
     *          If no default value is provided, it returns `null`.
     */
    sessionCookieGet<T>(key: string, defaultValue?: T): T | null;
}