/**
 * return the byte size of the string
 * @param str
 */
export declare function getByteLength(str: string): number;
/**
 * get current time
 */
export declare function getCurrentTime(): number;
/**
 * check if passed value is an integer
 */
export declare function isInteger(value?: number): boolean;
export declare const getCurrentSizeKey: (keyPrefix: string) => string;