Symfony - 在声明不兼容时定义变量

Question

I wrote a doctrine query builder to return all transactions by one card. So I call the $card variable in the other function and it throws:

Warning: Declaration of Service\SomeService::showFields(ShowMapper $showMapper, $card) should be compatible with Admin\AbstractAdmin::configureShowFields(ShowMapper $show)

As I ca't change syntax of this Admin Service or adding new instances I need a way out.

This is main function

 protected function configureShowFields(ShowMapper $showMapper, $card->this throws an error, it can't be set here)
{

    $transactions = $this->getTransactions($card);

...etc

and my doctrine query:

 public function getTransactions(Card $card)
{
    return $this->getTransactionRepository()
        ->createQueryBuilder('t')
        ->where('t.card = :card')
        ->setParameter('card', $card)
        ->orderBy(''desc')
        ->getQuery()
        ->getResult();
}

I tried:

 public $cards;

public function __construct(Card $cards)
{
    parent::__construct();
    $this->cards = $cards;
}

$cards = $this->cards;
 $transactions = $this->getTransactions($cards);

but it throws

Binding entities to query parameters only allowed for entities that have an identifier.