In client-side scripts, this method will return a transaction id for the async request that can be used to cancel the request. In server-side scripts, this method will return the JSON response object (first parameter of the success or failure callbacks.)
Saves the supplied security policy. This method will completely overwrite the existing policy for the resource. If another user has changed the policy in between the time it was selected and this method is called, the save will fail with an optimistic concurrency exception. To force your policy over the other, call the setModified() method on the policy passing null.