symfony/symfony — comment on commit d02f17268ecd2aed4730d4eb557733d5e038ed2e
File: tests/Symfony/Tests/Component/Form/Extension/Core/EventListener/MergeCollectionListenerCustomArrayObjectTest.php line 24
By canni:

Yep I know the difference between typecast and typehint, the goal is to not allow passing anything that is not an array, and typehint will emit error in that case, in case of passing `null` the `?:` it init empty array.