code: def set_label(self, label, lang=None):
          
          label = Validation.label_check_convert(label)
          lang = Validation.lang_check_convert(lang, default=self._default_lang)
          # remove any other labels with this language before adding
          self.delete_label(lang)
          subj = self._get_uuid_uriref()
          self._graph.add((subj, self._labelPredicate, Literal(label, lang)))
docs: Sets the `label` metadata property on your Thing/Point.  Only one label is allowed per language, so any
          other labels in this language are removed before adding this one
  
          Raises `ValueError` containing an error message if the parameters fail validation
  
          `label` (mandatory) (string) the new text of the label
  
          `lang` (optional) (string) The two-character ISO 639-1 language code to use for your label.
          None means use the default language for your agent.
          See [Config](./Config.m.html#IoticAgent.IOT.Config.Config.__init__)