How to use

contains

method

in

mage.cards.Cards

@Override
public boolean canPay(Ability ability, UUID sourceId, UUID controllerId, Game game) {
  Player player = game.getPlayer(controllerId);
  if (player != null && player.getHand().contains(sourceId)) {
    return true;
  }
  return false;
}

public Card getCard(UUID cardId, Game game) {
  for (Cards cards: this.values()) {
    if (cards.contains(cardId)) {
      return game.getCard(cardId);
    }
  }
  return null;
}

@Override
public boolean canPay(Ability ability, UUID sourceId, UUID controllerId, Game game) {
  Player player = game.getPlayer(controllerId);
  if (player != null && player.getHand().contains(sourceId)) {
    return true;
  }
  return false;
}

public Card getCard(UUID cardId, Game game) {
  for (Cards cards: this.values()) {
    if (cards.contains(cardId))
      return game.getCard(cardId);
  }
  return null;
}

@Override
public boolean canPay(Ability ability, UUID sourceId, UUID controllerId, Game game) {
  return game.getPlayer(controllerId).getHand().contains(sourceId);
}

@Override
public boolean canPay(Ability ability, UUID sourceId, UUID controllerId, Game game) {
  return game.getPlayer(controllerId).getHand().contains(sourceId);
}

public boolean hasBottomHalf(Game game) {
  boolean value = bottomLastZoneChangeCounter == bottomHalfCard.getZoneChangeCounter(game)
      && halves.contains(bottomHalfCard.getId());
  if (!value) {
    halves.remove(bottomHalfCard);
  }
  return value;
}

public boolean hasTopHalf(Game game) {
  boolean value = topLastZoneChangeCounter == topHalfCard.getZoneChangeCounter(game)
      && halves.contains(topHalfCard.getId());
  if (!value) {
    halves.remove(topHalfCard);
  }
  return value;
}

@Override
public boolean pay(Ability ability, Game game, UUID sourceId, UUID controllerId, boolean noMana, Cost costToPay) {
  Card card = game.getCard(sourceId);
  Player player = game.getPlayer(controllerId);
  if (player != null && player.getHand().contains(sourceId) && card != null) {
    paid = card.moveToExile(ability.getSourceId(), "from Hand", ability.getSourceId(), game);
  }
  return paid;
}

@Override
public boolean pay(Ability ability, Game game, UUID sourceId, UUID controllerId, boolean noMana, Cost costToPay) {
  Card card = game.getCard(sourceId);
  Player player = game.getPlayer(controllerId);
  if (player != null && player.getHand().contains(sourceId) && card != null) {
    paid = card.moveToExile(ability.getSourceId(), "from Hand", ability.getSourceId(), game);
  }
  return paid;
}

@Override
public boolean apply(Game game, Ability source) {
  JandorsRingWatcher watcher = game.getState().getWatcher(JandorsRingWatcher.class);
  return watcher != null
      && watcher.lastDrawnCards != null && game.getPlayer(source.getControllerId()).getHand().contains(watcher.getLastDrewCard(source.getControllerId()));
}

@Override
public void updateZoneChangeCounter(Game game, ZoneChangeEvent event) {
  if (isCopy() || !isMelded()) {
    super.updateZoneChangeCounter(game, event);
    return;
  }
  game.getState().updateZoneChangeCounter(objectId);
  if (topLastZoneChangeCounter == topHalfCard.getZoneChangeCounter(game)
      && halves.contains(topHalfCard.getId())) {
    topHalfCard.updateZoneChangeCounter(game, event);
    topLastZoneChangeCounter = topHalfCard.getZoneChangeCounter(game);
  }
  if (bottomLastZoneChangeCounter == bottomHalfCard.getZoneChangeCounter(game)
      && halves.contains(bottomHalfCard.getId())) {
    bottomHalfCard.updateZoneChangeCounter(game, event);
    bottomLastZoneChangeCounter = bottomHalfCard.getZoneChangeCounter(game);
  }
}

@Override
public boolean apply(Game game, Ability source) {
  Permanent discordantDirge = game.getPermanentOrLKIBattlefield(source.getSourceId());
  if (discordantDirge != null) {
    int verseCounters = discordantDirge.getCounters(game).getCount(CounterType.VERSE);
    Player targetOpponent = game.getPlayer(source.getFirstTarget());
    Player controller = game.getPlayer(source.getControllerId());
    if (targetOpponent != null
        && controller != null) {
      controller.lookAtCards(targetOpponent.getName() + " hand", targetOpponent.getHand(), game);
      TargetCard target = new TargetCard(0, verseCounters, Zone.HAND, new FilterCard());
      target.setNotTarget(true);
      if (controller.choose(Outcome.Benefit, targetOpponent.getHand(), target, game)) {
        target.getTargets().stream().map(game::getCard).filter((card) -> (card != null
            &&  targetOpponent.getHand().contains(card.getId()))).forEachOrdered((card) -> {
              targetOpponent.discard(card, source, game);
        });
        return true;
      }
    }
  }
  return false;
}

@Override
public boolean apply(Game game, Ability source) {
  Player opponent = game.getPlayer(targetPointer.getFirst(game, source));
  MageObject sourceObject = game.getObject(source.getSourceId());
  String cardName = (String) game.getState().getValue(source.getSourceId().toString() + ChooseACardNameEffect.INFO_KEY);
  if (opponent != null && sourceObject != null && !cardName.isEmpty()) {
    int costX = source.getManaCostsToPay().getX();
    if (costX > 0 && !opponent.getHand().isEmpty()) {
      Cards cards = new CardsImpl();
      while (costX > 0) {
        Card card = opponent.getHand().getRandom(game);
        if (!cards.contains(card.getId())) {
          cards.add(card);
          costX--;
        }
        if (opponent.getHand().size() <= cards.size()) {
          break;
        }
      }
      opponent.revealCards(sourceObject.getIdName(), cards, game);
      for (Card cardToDiscard : cards.getCards(game)) {
        if (cardToDiscard.getName().equals(cardName)) {
          opponent.discard(cardToDiscard, source, game);
        }
      }
    }
    return true;
  }
  return false;
}

while (player.isInGame() && cards.size() < numberOfCardsToDiscard) {
  Card card = player.getHand().getRandom(game);
  if (!cards.contains(card.getId())) {
    cards.add(card);

for (Card card : game.getCards()) {
  if (card.isOwnedBy(player.getId()) && !card.isCopy() // no copies
      && !player.getSideboard().contains(card.getId())

    return false;
} while (cards.contains(card.getId()));
cards.add(card);

if (isCopy()) { // copied cards have no need to be removed from a previous zone
  removed = true;
} else if (game.getPlayer(ownerId).getSideboard().contains(this.getId())) {
  game.getPlayer(ownerId).getSideboard().remove(this.getId());
  removed = true;

case HAND:
  for (Player player : getPlayers().values()) {
    if (player.getHand().contains(card.getId())) {
      player.getHand().remove(card);
      break;