Passing data to buildForm() in Symfony 3.3

AgencyController.php

/**
 * @Route("/agency/post", name="agency_post")
 */
public function agencyNewAd(Request $request)
{
   //  $agency = $this->get('security.token_storage')->getToken()->getUser(); ( this didn't worked .. )
    $form = $this->createForm(AgencyNewAdType::class, array(
        'postedBy' => $this->getUser(),
    ));
    $form->handleRequest($request);

    if ($form->isSubmitted() && $form->isValid()) {

        $ad = $form->getData();

        // save the task to the database
        $em = $this->getDoctrine()->getManager();
        $em->persist($ad);
        $em->flush();
        // return new Response('Saved new Post with id ' . $ad->getId());
        return $this->redirectToRoute('agency_admin');
    }
    return $this->render('agency/new_ad.html.twig', [
        'adForm' => $form->createView()
    ]);
}

AgencyNewAdType.php

class AgencyNewAdType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
    // https://stackoverflow.com/questions/36905490/how-to-pass-parameter-to-formtype-constructor-from-controller
    $builder
        ->add('title', TextType::class)
        ->add('content', TextareaType::class)
        ->add('category', EntityType::class, array(
            // query choices from Category.Name
            'class' => 'AppBundle:CategoryAd',
            'choice_label' => 'name',
        ))
        ->add('postedAt', DateType::class)
        ->add('postedBy',HiddenType::class, array(
            'data' => $options['postedBy']
        ))
        ->add('save', SubmitType::class, array('label' => 'Create Post'))
        ->getForm();

}
public function configureOptions(OptionsResolver $resolver)
   {
    $resolver->setDefaults(array(
        'postedBy' => null,
        'data_class' => 'AppBundle\Entity\AdsList',
    ));
   }
}

public function agencyNewAd(Request $request)
{
    $ad = new AdsList();
    $form = $this->createForm(new AgencyNewAdType($this->getUser(), $ad);
}

class AgencyNewAdType extends AbstractType
{
    private $user;

    public function __construct(User $user)
    {
        $this->user = $user;
    }

   public function buildForm(FormBuilderInterface $builder, array $options)
   {
        $builder
        ->add('postedBy',HiddenType::class, array(
            'data' => $this->user
        ))

    } 
}

Parse error: syntax error, unexpected 'private' (T_PRIVATE)
PHPstorm says

private $user; $user is undefined

$this->user Field 'user' not found in AgencyNewAdType less...
Referenced field is not found in subject class. Note: Check is not performed on objects of type "stdClass" or derived.