I am using the PHP Google client library. I successfully get a token and refresh token from user/google to use with the API.
As soon as the user revokes the permission for my website in Googles settings on the Google page i get following error:

```
Error calling GET https://www.googleapis.com/calendar/v3/users/me/calendarList: (401) Invalid Credentials

```

That is expected behavior since the user revoked my permission.
However, how do I detect that a user revoked that access?

Currently i do the following to see if i have access:

```
//$token json fetched from database
$gclient->setAccessToken($token);
if ($gclient->getAccessToken())
    //i should have access

```

Well this code unfortunately does not detect the revoked permission. How can i handle that?