import { StringObject } from '../shared';
export declare class BadCurpFormat extends Error {
    constructor(curp: string);
}
export declare class Curp extends StringObject {
    private readonly curpIdPattern;
    constructor(curpId: string);
    get state(): string;
    getIsoState(): Promise<string>;
    private ensure;
    private toUpperCase;
    private ensureCurpId;
    private isNotUndefined;
}