':return: a pivot iterator - see _get_pivot_iterator()'

def _many_to_one_pivot(self, base_objects_by_id, related_model, foreign_key_field):

    filter_data = {(foreign_key_field.name + '__pk__in'): base_objects_by_id.keys()}
    for related_object in related_model.objects.filter(**filter_data):
        base_object_id = getattr(related_object, foreign_key_field.attname)
        base_object = base_objects_by_id[base_object_id]
        (yield (base_object, related_object))
