export function uuid_v4() {
    // @ts-ignore
    return ([1e7] + - 1e3 + - 4e3 + - 8e3 + - 1e11).replace(/[018]/g, c =>
        // tslint:disable-next-line:no-bitwise
        (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
    );
}