function toISODateString(d) {
    function pad(n) { return n < 10 ? '0' + n : n }
    return d.getUTCFullYear() + '-'
        + pad(d.getUTCMonth() + 1) + '-'
        + pad(d.getUTCDate()) + 'T'
        + pad(d.getUTCHours()) + ':'
        + pad(d.getUTCMinutes()) + ':'
        + pad(d.getUTCSeconds()) + 'Z'
}

function sleep(ms){
    return new Promise(resolve=>{
        setTimeout(resolve,ms)
    })
}

exports.toISODateString = toISODateString;
exports.sleep = sleep;