function createPromises(length) {
    const promises = [];
    for (let i = 0; i < length; i += 1) {
        const value = Math.random();
        promises.push(new Promise((resolve, reject) => setTimeout(() => {
            if (value < 0.1) reject('exception');
            resolve(value);
        }, value * 1000)));
 }

function* iterate(length) {
    for (let i = 1; i <= length; i += 1) yield i;
}

function* pow2(array) {
    for (let i in array) yield array[i] ** 2;
}

const res = [...pow2([...iterate(10)])]; // (10) [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]

function camel(object) {
    const keys = Object.keys(object);
    return keys.reduce((o, k) => {
        if (k.includes('_')) {
            const words = k.split('_');
            const capitalized = words.map((word, i) => {
                if (word.length > 0) {
                    const capital = i > 0 ? `${word[0].toUpperCase()}${word.substr(1)}` : word;
 return capital;