Binding and persisting configuration updates


I have been reworking the nest binding to get it working, and got it almost completely working now except I cannot persist the configuration updates to save the access token I need to access nest. I do this in the bridge handler code:
// Update the configuration and persist to the database.
Configuration configuration = editConfiguration();
configuration.put(“accessToken”, stringAccessToken);

However I don’t see any updates into the json database so the accessToken doesn’t seem to be saved. What should I be doing?