Update Document By Key Value WIth JSON Object

Question

Hi Guys, I'm newbie here.

  I'm currently following the code here http://api.shephertz.com/app42-docs/nosql-storage-service/#update-document-by-key-value-with-json-object . It says that "This key value pair will be searched in the JSON doc stored in the cloud and matching doc will be updated with new value passed" but it doesn't update even with the same key value like on the sample instead it just insert a new json object to the collection. I don't even change the key = "name" and the value = "Nick" like on the sample so it must be search and updated. I'm using cocos2d-x. Can someone clarify this to me? thanks.