Illuminate\Support\Collection::chunk PHP Method

    public function chunk($size)
    {
        if ($size <= 0) {
            return new static();
        }
        $chunks = [];
        foreach (array_chunk($this->items, $size, true) as $chunk) {
            $chunks[] = new static($chunk);
        }
        return new static($chunks);
    }

 /**
  * @param Collection             $devices
  * @param ApnsService|GcmService $service
  *
  * @return array
  */
 private function sendToService(Collection $devices, $service)
 {
     /** @var Collection $chunks */
     $chunks = $devices->chunk((int) config('push.chunk', 100));
     $results = ['errors' => [], 'updates' => []];
     foreach ($chunks as $chunk) {
         $this->mergeResults($results, $service->push($chunk));
     }
     return $results;
 }