public function postSave(Request $request)
 {
     $post_fields_arr = $request->all();
     $validator = \Validator::make($post_fields_arr, ['name' => 'required|max:100', 'description' => 'max:255']);
     if ($validator->fails()) {
         return 'Невалидные данные';
     }
     $post_fields_arr['user_id'] = $this->user->id;
     if (isset($post_fields_arr['id'])) {
         $widget_model = \App\Models\PricingGridModel::find($post_fields_arr['id']);
         if (!$widget_model) {
             return 'Ошибка: нет виджета с таким ID - ' . $post_fields_arr['id'];
         }
         $widget_model->name = $post_fields_arr['name'];
         $widget_model->description = $post_fields_arr['description'];
         $widget_model->save();
     } else {
         \App\Models\PricingGridModel::create($post_fields_arr);
     }
     return redirect('/seller/pricing-grids');
 }