code: def add_package_repo(
          repo_name,
          repo_url,
          index=None,
          wait_for_package=None,
          expect_prev_version=None):
      
  
      package_manager = _get_package_manager()
      if wait_for_package:
          prev_version = package_manager.get_package_version(wait_for_package, None)
      if not package_manager.add_repo(repo_name, repo_url, index):
          return False
      if wait_for_package:
          try:
              spinner.time_wait(lambda: package_version_changed_predicate(package_manager, wait_for_package, prev_version))
          except TimeoutExpired:
              return False
      return True
docs: Add a repository to the list of package sources
  
          :param repo_name: name of the repository to add
          :type repo_name: str
          :param repo_url: location of the repository to add
          :type repo_url: str
          :param index: index (precedence) for this repository
          :type index: int
          :param wait_for_package: the package whose version should change after the repo is added
          :type wait_for_package: str, or None
  
          :return: True if successful, False otherwise
          :rtype: bool