declare const testHelper: {
    obj: {
        r: number;
    };
    num: number;
    str: string;
    reg: RegExp;
    retJSONObject(): {
        r: number;
    };
    retNumber(): number;
    retString(): string;
    retReg(): RegExp;
    retUnserializableObject(): {
        r: number;
        self: Window & typeof globalThis;
    };
    retBool(): boolean;
    retNull(): null;
    retUndefined(): undefined;
    callbackNum(callback: any): void;
    callbackUnserializable(callback: any): void;
};
export default testHelper;