docs: def names():
      '''
      Lazy-load the tree of names, and return them in an object.
      Of course, asterisks etc. cannot be resolved, you should use allowed() to
      check for a valid name.
      '''
      global blacklist
      if blacklist is None:
          # not yet loaded
          path = os.path.join(os.path.dirname(__file__), 'names.yaml')
          f = open(path, 'r')
          blacklist = yaml.safe_load(f)
          f.close()
      return blacklist