def _triples_url(self, graph_type='instance'):
    if (self._db == '_system'):
        base_url = self._db_base('triples')
    else:
        base_url = self._branch_base('triples')
    return f'{base_url}/{graph_type}'
def _triples_url(self, graph_type='instance'):
    if (self._db == '_system'):
        base_url = self._db_base('triples')
    else:
        base_url = self._branch_base('triples')
    return f'{base_url}/{graph_type}'