'Return the related field name of the m2m on Tag.'

@classmethod
def _get_m2m_name(cls, obj):

    related_models = cls._meta.get_all_related_m2m_objects_with_model()
    field_map = {rm[0].related_model: rm[0].field.name for rm in related_models}
    return field_map.get(obj._meta.model)
