Function aggregate

tools/load-test.js:126–135

(objs)

 * }
 */
function aggregate(objs) {
    const ret = {};
    for (let obj of objs) {
        for (let key in obj) {
            if (!(key in ret)) ret[key] = [];
            ret[key] = ret[key].concat(obj[key]);
        }
    }
    return ret;
}

async function sleep(sec) {
    return new Promise(resolve => setTimeout(resolve, sec * 1000));