code: def get_and_check_project(valid_vcs_rules, source_url):
      
      project_path = match_url_regex(valid_vcs_rules, source_url, match_url_path_callback)
      if project_path is None:
          raise ValueError("Unknown repo for source url {}!".format(source_url))
      project = project_path.split('/')[-1]
      return project
docs: Given vcs rules and a source_url, return the project.
  
      The project is in the path, but is the repo name.
      `releases/mozilla-beta` is the path; `mozilla-beta` is the project.
  
      Args:
          valid_vcs_rules (tuple of frozendicts): the valid vcs rules, per
              ``match_url_regex``.
          source_url (str): the source url to find the project for.
  
      Raises:
          RuntimeError: on failure to find the project.
  
      Returns:
          str: the project.