AccessToken Error recovery in Auth2 (Android)

Functionally, I now have Core API v2 integrated into my app and working well.  I have decided to create a dynamic DbxClientV2, rather than as a static as shown in the official sample code, and it seems to be working well.  Does anyone know if this is in accord with best practices?  I release the DbxClientV2 after each session of working with Dropbox, which is small part of my app.  But it is possible to have several Dropbox sessions during the lifetime of my app.

So the first question remains:  what will happen if my accessToken is faulty for some reason, even if it was good at one time?  Here is the sequence of API calls that I do with accessToken (download from the root folder):

sDbxClient = new DbxClientV2(requestConfig, accessToken);

ListFolderResult result = sDbxClient.files().listFolder(");

List<Metadata> list = result.getEntries();

I imagine that if accessToken was bad, something would go wrong before this point.  So, which call would fail, and how?  (What exception, what null return, etc.?)