$items->put('products', $product);
$collection = collect([1, 2, 3, 4]);
$collection->push(5);
$collection->all();
// [1, 2, 3, 4, 5]
$collection = collect([1,2,3,4]);
$collection->each(function($item){
return $item*$item;
});
// [1,4,9,16]