Return transactions result

If you have a DB transaction and want to return its result, there are at least two ways, see the example

 1// 1. You can pass the parameter by reference
 2$invoice = NULL;
 3DB::transaction(function () use (&$invoice) {
 4    $invoice = Invoice::create(...);
 5    $invoice->items()->attach(...);
 6})
 7 
 8// 2. Or shorter: just return trasaction result
 9$invoice = DB::transaction(function () {
10    $invoice = Invoice::create(...);
11    $invoice->items()->attach(...);
12 
13    return $invoice;
14});