In yt stream extractor test.
The Vevo and the normal music channel are equivalent, so Youtube picks one of them at random, and in playerResponse the channel id is Vevo's one.
- Handle special cases for languages where the number is not shown
- Rework the Downloader base implementation, allowing for more
advanced things to be done
- Separate the localization from the content country (just like
YouTube let's the user choose both).