public void PutCardInStack(CardAnimator cardAnimator, Card card)
{
Debug.Log("DisplayingCards.Remove(card) " + card);
card.isInStack = true;
card.isTouchable = false;
card.SetFaceUp(true);
DisplayingCards.Remove(card);
DisplayingBooks.Remove(card);
HiddenBooks.Remove(card);
cardAnimator.AddCardToStack(card);
NumberOfDisplayingCards--;
RepositionDisplayingCards(cardAnimator);
}