def _deduplicate_values(self, value):
        # deduplicate given values to avoid creating many querysets or
        # requiring the database backend deduplicate efficiently.
        try:
            return frozenset(value)
        except __HOLE__:
            # list of lists isn't hashable, for example
            raise forms.ValidationError(
                self.error_messages['list'],
                code='list',
            )
dataset/ETHPy150Open yourlabs/django-autocomplete-light/src/dal_queryset_sequence/fields.py/QuerySetSequenceModelMultipleField._deduplicate_values