code: function pickTags() {
    var picked = [];
    var max = Math.floor(Math.random() * maxTags);
    while(picked.length < max) {
      var tag = pickTag();
      if (picked.indexOf(tag) === -1) {
        picked.push(tag);
      }
    }
    return picked;
  }
docs: pick random tags up to the `maxTags`