Google Cloud使用JavaScript / REST保存获得409冲突

Question

所以我正在尝试实施google appstate云保存功能来保存字符串（https://developers.google.com/games/services/web/api/states），但我收到409冲突错误。我必须错误地使用它。有没有人有任何JavaScript实现的例子？ 这就是我的方式：

GET https://www.googleapis.com/appstate/v1/states

返回：

{
 "kind": "appstate#listResponse",
 "maximumKeyCount": 4,
 "items": [
  {
   "kind": "appstate#getResponse",
   "stateKey": 0,
   "currentStateVersion": "CNDVopDDwLgC"
  }
 ]
}

然后我

PUT https://www.googleapis.com/appstate/v1/states/0

身体：

{

currentVersion: "CNDVopDDwLgC"
data: "some data"
kind: "appstate#updateRequest"

}

给出错误：409 Conflict

{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "OutOfDateVersion",
    "message": "The resource version you are attempting to modify does not match the current version on the server."
   }
  ],
  "code": 409,
  "message": "The resource version you are attempting to modify does not match the current version on the server."
 }
}

有谁知道我做错了什么？