Laravel Parse Custom Validation

Validator::extend('object_exists', function ($attribute, $value, $parameters, $validator) {
    $class = '\App\\' . ucfirst($parameters[0]);

    if (is_array($value)) {
        foreach ($value as $id) {
            $object = call_user_func([$class, 'find'], $id);
            if (is_null($object)) return false;
        }
        return true;
    }

    $object = call_user_func([$class, 'find'], $value);
    return $object == null ? false : true;
});

Validator::extend('value_unique', function ($attribute, $value, $parameters, $validator) {
    $class = '\App\\' . ucfirst($parameters[0]);
    $object = call_user_func([$class, 'where'], $attribute, $value)->first();
    return $object == null ? true : false;
});