protected function updateOrCreateBelongsToOne(array $fillable, Model $model, Relation $relation)
    {
        $related = $relation->getRelated();

        if (array_except($fillable, ['id'])) {
            if (!$relation->first()) {
                $record = $relation->associate($related->create($fillable));
                $model->save();
            } else {
                $record = $relation->update($fillable);
            }

            return $record;
        }

        return null;
    }