docs: function set$1 (obj, key, val) {
    if (Array.isArray(obj)) {
      obj.length = Math.max(obj.length, key);
      obj.splice(key, 1, val);
      return val
    }
    if (hasOwn(obj, key)) {
      obj[key] = val;
      return
    }
    var ob = obj.__ob__;
    if (obj._isVue || (ob && ob.vmCount)) {
      process.env.NODE_ENV !== 'production' && warn(
        'Avoid adding reactive properties to a Vue instance or its root $data ' +
        'at runtime - declare it upfront in the data option.'
      );
      return
    }
    if (!ob) {
      obj[key] = val;
      return
    }
    defineReactive$$1(ob.value, key, val);
    ob.dep.notify();
    return val
  }