How to simulate non existing method error in __call?

How to simulate non existing method error in __call?

Maybe strange question, but... I have a magic __call method, that return instances of certain classes, or, if there are no such class, calls same method in underlying object.
public function __call($name, $arguments)
{
    $class = 'My\\Namespace\\' . $name;

    if (class_exists($class, true)) {

        $reflect = new \ReflectionClass($class);
        return $reflect->newInstanceArgs($arguments);

    } elseif (is_callable([$this->connector, $name])) {

        return call_user_func_array([&$this->connector, $name], $arguments);
    } else {
        // ????
    }
}
But what to do in else block? Can I simulate undefined method error? Or what exception to throw would be correct?