docs: def guess_depth(packages):
      """
      Guess the optimal depth to use for the given list of arguments.
  
      Args:
          packages (list of str): list of packages.
  
      Returns:
          int: guessed depth to use.
      """
      if len(packages) == 1:
          return packages[0].count('.') + 2
      return min(p.count('.') for p in packages) + 1