Call to undefined method Nette\Application\UI\Multiplier::render()

Hello to all!

I have presenter:

	protected function createComponentMaterialsForm() {
		$form = new \Nette\Application\UI\Form;
		$form->addText('count', 'Count');
		$form->addSubmit('send', 'Add');
		return $form;
	}

and template:

	{block viewContent}
		{control materialsForm}
	{/block}

Everything works. But when I use Multiplier:

	protected function createComponentMaterialsForm() {
		return new \Nette\Application\UI\Multiplier(function () {
			$form = new \Nette\Application\UI\Form;
			$form->addText('count', 'Count');

			$form->addSubmit('send', 'Add');
			return $form;
		});
	}

I'm getting Nette\MemberAccessException Call to undefined method Nette\Application\UI\Multiplier::render(). Can someone explain me why? Thanks…