Currently, nothing calls this.  Either parse() should support some flags to control logging verbosity (they should take effect as soon as parse() sees them, so that they can affect parsing verbosity; no need to record on the config structure), or you can massively simplify all the logging code by knowing what the current logging level is.  Of course, you can legitimately claim you've chosen the former but are deferring its implementation until later, a perfectly good reason to leave it as it currently is.