Clear both ontology and annotation data.

        Parameters
        ----------

        Returns
        -------
        None

def clear_data(self):
        """Clear both ontology and annotation data.

        Parameters
        ----------

        Returns
        -------
        None
        """
        self.clear_annotation_data()
        self.terms = {}
        self._alt_id = {}
        self._syn2id = {}
        self._name2id = {}
        self._flattened = False