import { Mfk } from './mfk';
/**
 * checks the equality of two Mfk objects
 * @param mfk1 an Mfk object
 * @param mfk2 an Mfk object
 */
export declare function areEqual(mfk1: Mfk, mfk2: Mfk): boolean;
/**
 * converts an Mfk object to a string by joining 10 fields with '-' symbol.
 * @param mfk An Mfk object
 */
export declare function stringify(mfk: Mfk | null): string;
/**
 * creates an empty Mfk object with all 10 fields being empty string
 */
export declare function emptyMfk(): Mfk;
/**
 * checks if an Mfk object is in a valid format
 */
export declare function validFormat(mfk: Mfk): boolean;
/**
 * checks if each field of an Mfk object is in a valid format
 * returns an array of error messages
 * If the format is valid, then the returning array is empty.
 */
export declare function validateStructure(mfk: Mfk): string[];
/**
 * Convert a string to an MFK object
 * @param mfkString MFK string
 * @returns MFK object
 */
export declare function toMfk(mfkString: string): Mfk;