def METHOD_NAME(self):
    if self.queryset is not None:
        queryset = self.queryset
    elif hasattr(self.choices, 'queryset'):
        queryset = self.choices.queryset
    else:
        raise NotImplementedError(
            '%(cls)s is missing a QuerySet. Define '
            '%(cls)s.queryset, or override '
            '%(cls)s.get_queryset().' % {'cls': self.__class__.__name__}
        )
    return queryset