private function serializeHand(Hand $hand = null)
 {
     if ($hand === null) {
         return null;
     }
     return ['value' => $hand->getValue(), 'canSplitHand' => $hand->canSplitPair(), 'cards' => $hand->getCards()->map(function (Card $card) {
         return $this->serializeCard($card);
     })->elements()];
 }
 private function serializeHand(Hand $hand = null)
 {
     if ($hand === null) {
         return null;
     }
     return ['value' => $hand->getValue(), 'cards' => $hand->getCards()->map(function (Card $card) {
         return ['rank' => $card->getRank(), 'suit' => $card->getSuit()];
     })->elements()];
 }