as far as I understand it, This line here

https://github.com/mozilla/mozdownload/blob/master/mozdownload/scraper.py#l85

decides what log level we have. Therefore, when calling a scraper in a test, I need to announce that we want the ERROR log_level. I found it best to do it this way, so that we can selectively switch on the INFO output for each section (depending on which test failed).

RE: relationship between `log_level` and `getEffectiveLevel()`
`log_level` is directly used and not kept in a variable, as a consequence, I need to call `getEffectiveLevel()` to regain information about the current log level. I could have created `self.log_level` instead, but I chose that way. Would you prefer it the other way round?