How to use validation rules for list args?

[drewgallagher]

Is there a way to validate each value in a list arg with validation rules?

This is what we currently have but I'm not sure if it validates each value in excluded_slugs or just if any one of them passes.

    public function args(): array
    {
        return [
            'id' => ['name' => 'id', 'type' => Type::int()],
            'name' => ['name' => 'name', 'type' => Type::string()],
            'excluded_slugs' => ['name' => 'excluded_slugs', 'type' => Type::listOf(Type::string()), 'description' => 'Departments to exclude based on slug', 'rules' => ['exists:departments,slug']],
        ];
    }