code: def safejoin(base, *elements):
      
      # TODO: do we really want to be absolute here?
      base = os.path.abspath(base)
      path = os.path.join(base, *elements)
      path = os.path.normpath(path)
      if not path_is_inside(path, base):
          raise ValueError('target path is outside of the base path')
      return path
docs: Safely joins paths together.
  
      The result will always be a subdirectory under `base`, otherwise ValueError
      is raised.
  
      Args:
          base (str): base path
          elements (list of strings): path elements to join to base
  
      Returns:
          elements joined to base