def set_raw_field_value(self, instance, field_name, value):
        field = instance._meta.get_field(field_name)
        setattr(instance, field.attname, value)
Sets the value of the given fieldname for the instance.
dataset/ETHPy150Open django-mptt/django-mptt/mptt/models.py/MPTTOptions.set_raw_field_value