code: def parse_repo_slug_from_url(github_url):
      
      match = GITHUB_SLUG_PATTERN.match(github_url)
      if not match:
          message = 'Could not parse GitHub slug from {}'.format(github_url)
          raise RuntimeError(message)
  
      _full = '/'.join((match.group('org'),
                        match.group('name')))
      return RepoSlug(_full, match.group('org'), match.group('name'))
docs: Get the slug, <owner>/<repo_name>, for a GitHub repository from
      its URL.
  
      Parameters
      ----------
      github_url : `str`
          URL of a GitHub repository.
  
      Returns
      -------
      repo_slug : `RepoSlug`
          Repository slug with fields ``full``, ``owner``, and ``repo``.
          See `RepoSlug` for details.
  
      Raises
      ------
      RuntimeError
          Raised if the URL cannot be parsed.