docs: def _normalize_check_url(self, check_url):
          """
          Normalizes check_url by:
  
          * Adding the `http` scheme if missing
          * Adding or replacing port with `self.port`
          """
  
          # TODO: Write tests for this method
          split_url = urlsplit(check_url)
          host = splitport(split_url.path or split_url.netloc)[0]
          return '{0}://{1}:{2}'.format(self.scheme, host, self.port)