Sub Doc Operations Expected Response

Is there any Docs avail what the expected response for a successful Sub Doc Delete operation is.
In my case i

      .execute((err, result) 

and my result looks like this which really doesn’t tell you much

“cas”: “1553198421978382336”,
“contents”: [
“id”: 0,
“value”: ,
“path”: “emails”
“pathMap”: null,
“indexMap”: null

is there anyplace i can see if it succeeded short of query the doc again ?