Simplify interface of Google examples and fix the name and comment of userName variable

> This is why I decided to keep these try blocks separate.

Fair point - they are a little different, indeed. I was just wondering if there was some way to reduce the amount of code duplication we now have for just a slight difference in error messages. How about putting them in _one_ block with a message such as: "Unable to load your SSH keys. Please ensure your public key, used for X, is at ... and your private key, needed for Y, is at ..."?

But also OK to leave as-is - your call.