def get_for_object(self, obj, **kwargs):
        ctype = ContentType.objects.get_for_model(obj)
        extra_args = {}
        if 'field' in kwargs:
            extra_args['supertaggeditem__field'] = kwargs['field']
        order_by = kwargs.get('order_by', '-relevance')
        
        return self.filter(
            supertaggeditem__content_type__pk=ctype.pk,
            supertaggeditem__object_id=obj.pk,
            **extra_args).annotate(
                relevance=models.Max('supertaggeditem__relevance')
            ).order_by(order_by)
Returns tags for an object, also returns the relevance score from 
dataset/ETHPy150Open callowayproject/django-supertagging/supertagging/models.py/SuperTagManager.get_for_object