export default class Core {
    private static _instance;
    private options;
    private coreDatabase;
    private coreStorage;
    private browserStorage;
    private fastDataService;
    private nqsService;
    private commonVariables;
    private registeredPeriodicPushes;
    static getInstance(accountCode?: string): Core;
    private constructor();
    /**
     * Return the Unified Plugin versions
     */
    static getPluginVersion(): string;
    /**
     * Stores a common value for a product that might need to be used by other products
     *
     * @param productKey Product identifier (e.g. balancer)
     * @param variableKey Variable identifier (e.g. balancer-id)
     * @param value Value to be stored
     */
    registerCommonVariable(productKey: string, variableKey: string, value: any): void;
    /**
     * Deletes a common variable for the specified product
     * @param productKey Product identifier (e.g. balancer)
     * @param variableKey Variable identifier (e.g. balancer-id)
     */
    unregisterCommonVariable(productKey: string, variableKey: string): void;
    /**
     * Fetches the value stored for a product and variable identifiers
     *
     * @param productKey Product identifier (e.g. balancer)
     * @param variableKey Variable identifier (e.g. balancer-id)
     * @returns The value of the variable associated with the product or undefined if it is not set
     */
    getCommonVariable(productKey: string, variableKey: string): any | undefined;
    /**
     *
     * @returns The FastData service session token
     */
    getFastDataSessionToken(): string;
    /**
     * Refreshes the session token
     */
    refreshSessionToken(): void;
    /**
     *
     * @returns true if the session token is expired, false otherwise
     */
    isSessionTokenExpired(): boolean;
}