Continued:

Continued:
- moved if() block to suggested position by MrPetovan, for me I want to have all
  conditions checked at the start of the method, e.g. no unwanted null
  references or (in this case) if the URL is blacklisted
- normalized URLs are without SSL, means http://host/path/file.ext so they exist
  only once for contacts and servers (aka. instances)
- documented returned type `void`