/**
  * Gets the deck of Cards to deal to the Players.
  *
  * @param solution The Cards that have been removed from the deck.
  * @return A List of the Cards that remain to deal to Players.
  */
 private List<Card> getDeck(Suggestion solution) {
   List<Card> deck = Card.getCards();
   deck.removeAll(solution.getCards());
   return deck;
 }