code: def flags(self, flags):
          
          if isinstance(flags, (six.text_type, bytes)):
              flags = flags.split()
          self._flags = [x.lower() for x in flags]
          self.name_is_unique = 'named' in self._flags
docs: It might be nice to make flags not a list of strings. This is
          made harder by the control-spec: `...controllers MUST tolerate
          unrecognized flags and lines...`
  
          There is some current work in Twisted for open-ended constants
          (enums) support however, it seems.