Methods and functions with return type declaration `void` or `never` can not be mocked to throw an Exception: ```php class Example { public function store(string $something): void { ... } } $mock = NewInstance::of(Example::class) $mock->returns(['store' => throws(new Exception('failure'))]); ``` InvalidArgumentException: Trying to map method Example::store(), but it is declared as returning void or never. It should be possible to throw an exception from such a method, while providing a regular return value should still be forbidden.