hello

example.php

<?php

interface Identity {
    public function getID(): string;
}

class User implements Identity {
    public function getID(): string {
        return "3a85dea1-061a-4296-9fe5-514ade8ee969";
    }
}

interface Repository {
    public function save(Identity $item);
}

class UserRepository implements Repository {
    public function save($item) { # accidental type-hint omission - succeeds
        // ...
    }
}

$user = new User();

$repo = new UserRepository();

$repo->save(new stdClass()); // call succeeds - failure (hopefully) occurs deep in some other code?