docs: function zip(xs, ys) {
    var zipped = [];
  
    if (!isArray(xs) || !isArray(ys)) throw new Error(messages.InputMustBeArray);
    xs = xs.slice();
    ys = ys.slice();
    while (xs.length && ys.length) zipped.push([xs.shift(), ys.shift()]);
    return zipped;
  }