def clear(self, category=None):
        if not category:
            getattr(self.obj, self._m2m_fieldname).clear()
        else:
            getattr(self.obj, self._m2m_fieldname).filter(db_category=category).delete()
        self._recache()
Does datashape contain only one dtype?
dataset/ETHPy150Open evennia/evennia/evennia/typeclasses/tags.py/TagHandler.clear--crossover with--dataset/ETHPy150Open blaze/datashape/datashape/predicates.py/ishomogeneous