How can i use field credentials for symfony admin generator forms?

public function preExecute()
{
  parent::preExecute();
 
  $this->configuration->setUser($this->getUser());
}

protected $user;
 
public function setUser($user)
{
  $this->user = $user;
}
 
public function getUser()
{
  return $this->user;
}
 
public function getEditDisplay()
{
  $fieldsets = parent::getEditDisplay();
  if (!$this->getUser()->hasCredential('admin'))
  {
    unset(
      $fieldsets['Auth'][2], // field
      $fieldsets['Rights']   // field group
    );
  }
 
  return $fieldsets;
}
 
public function getNewDisplay()
{
  ... // see getEditDisplay
}
 
public function getFormOptions()
{
  return array('user' => $this->getUser());
}

public function configure()
{
  ...
  if (!$this->getOption('user')->hasCredential('admin'))
  {
    unset($this['is_super_admin'], $this['groups_list'], $this['permissions_list']);
  }
  ...
}