def save_existing(self, form, instance, commit=True):
        """
        NOTE: save_new method is completely overridden here, there's no
        other way to pretend double save otherwise. Just assign translated data
        to object  
        """
        self._prepare_multilingual_object(instance, form)
        return forms.save_instance(form, instance, exclude=[self._pk_field.name], commit=commit)