[Sidetiq uses the arity of `OauthTokenRefreshScheduleWorker#perform`](https://github.com/tobiassvn/sidetiq/blob/master/lib/sidetiq/handler.rb#L40-L47) to determine which values to add as job arguments. In order to get `current_occurrence`, `perform` must take two arguments.

`perform` should have a docstring anyway. I'll note this property of Sidetiq there.