protected function processSort(array $models = [])
{
$field = $this->builder->getSortByField();
$flags = $this->builder->getSortByFlags();
$direction = $this->builder->getSortByDirection();
$desc = $direction === 'desc' ? true : false;
return $this->newCollection($models)->sortBy(function (Model $model) use($field) {
return $model->getAttribute($field, 0);
}, $flags, $desc);
}