protected function findViewColumns(Builder $builder, Collection $collection)
 {
     if ($columns = $builder->getColumns()) {
         return $columns;
     }
     $src = $collection->getSrc();
     if (!count($src)) {
         return [$builder->model()->getKeyName()];
     }
     $firstResult = $src[0];
     return array_keys($firstResult->getAttributes());
 }
 protected function findViewColumns(Search $search, Collection $collection)
 {
     if ($columns = $search->keys()) {
         return $columns;
     }
     $src = $collection->getSrc();
     $modelClass = $search->modelClass();
     $rootModel = new $modelClass();
     if (!count($src)) {
         return [$rootModel->getKeyName()];
     }
     $firstResult = $src[0];
     return array_keys($firstResult->getAttributes());
 }