docs: def unlist(list_thing, complain=True):
      """transforms [Something] -> Something. By default, raises a ValueError for
      any other list values."""
      if complain and len(list_thing) > 1:
          raise ValueError("More than one element in {}".format(list_thing))
      elif len(list_thing) == 1:
          return list_thing[0]
  
      if complain:
          raise ValueError("Nothing in {}".format(list_thing))
      return None