Program: 159309
Project: 159309
Buggy source:
@Override public boolean apply(Game game,Ability source){
  Player you=game.getPlayer(source.getControllerId());
  if (you == null) {
    return false;
  }
  Cards pile2=new CardsImpl();
  int max=Math.min(you.getLibrary().size(),5);
  for (int i=0; i < max; i++) {
    Card card=you.getLibrary().removeFromTop(game);
    if (card != null) {
      card.moveToExile(source.getSourceId(),"String_Node_Str",source.getId(),game);
      pile2.add(card);
    }
  }
  Player opponent=game.getPlayer(source.getFirstTarget());
  if (opponent != null) {
    TargetCard target=new TargetCard(0,pile2.size(),Zone.EXILED,new FilterCard("String_Node_Str"));
    Cards pile1=new CardsImpl();
    List<Card> pileOne=new ArrayList<Card>();
    List<Card> pileTwo=new ArrayList<Card>();
    if (opponent.choose(Outcome.Neutral,pile2,target,game)) {
      List<UUID> targets=target.getTargets();
      for (      UUID targetId : targets) {
        Card card=pile2.get(targetId,game);
        if (card != null) {
          pile1.add(card);
          pile2.remove(card);
        }
      }
    }
    for (    UUID cardID : pile1) {
      Card card=pile1.get(cardID,game);
      pileOne.add(card);
    }
    for (    UUID cardId : pile2) {
      Card card=pile2.get(cardId,game);
      pileTwo.add(card);
    }
    you.revealCards("String_Node_Str",pile1,game);
    you.revealCards("String_Node_Str",pile2,game);
    boolean choice=you.choosePile(Outcome.PlayForFree,"String_Node_Str",pileOne,pileTwo,game);
    if (choice) {
      game.informPlayer(you,you.getName() + "String_Node_Str");
      while (!pileOne.isEmpty() && you.chooseUse(Outcome.PlayForFree,"String_Node_Str",game)) {
        TargetCard targetExiledCard=new TargetCard(Zone.EXILED,new FilterCard());
        if (you.chooseTarget(Outcome.PlayForFree,pile1,targetExiledCard,source,game)) {
          Card card=pile1.get(targetExiledCard.getFirstTarget(),game);
          if (card != null) {
            if (card.getCardType().contains(CardType.LAND)) {
              you.playLand(card,game);
              pileOne.remove(card);
              pile1.remove(card);
            }
 else {
              you.cast(card.getSpellAbility(),game,true);
              pileOne.remove(card);
              pile1.remove(card);
            }
          }
        }
      }
    }
 else {
      game.informPlayer(you,you.getName() + "String_Node_Str");
      while (!pileTwo.isEmpty() && you.chooseUse(Outcome.PlayForFree,"String_Node_Str",game)) {
        TargetCard targetExiledCard=new TargetCard(Zone.EXILED,new FilterCard());
        if (you.chooseTarget(Outcome.PlayForFree,pile2,targetExiledCard,source,game)) {
          Card card=pile2.get(targetExiledCard.getFirstTarget(),game);
          if (card != null) {
            if (card.getCardType().contains(CardType.LAND)) {
              you.playLand(card,game);
              pileTwo.remove(card);
              pile2.remove(card);
            }
 else {
              you.cast(card.getSpellAbility(),game,true);
              pileTwo.remove(card);
              pile2.remove(card);
            }
          }
        }
      }
    }
    return true;
  }
  return false;
}

Fixed version (ground truth):
@Override public boolean apply(Game game,Ability source){
  Player you=game.getPlayer(source.getControllerId());
  if (you == null) {
    return false;
  }
  Cards pile2=new CardsImpl();
  int max=Math.min(you.getLibrary().size(),5);
  for (int i=0; i < max; i++) {
    Card card=you.getLibrary().removeFromTop(game);
    if (card != null) {
      card.moveToExile(source.getSourceId(),"String_Node_Str",source.getId(),game);
      pile2.add(card);
    }
  }
  Player opponent=game.getPlayer(source.getFirstTarget());
  if (opponent != null) {
    TargetCard target=new TargetCard(0,pile2.size(),Zone.EXILED,new FilterCard("String_Node_Str"));
    target.setRequired(false);
    Cards pile1=new CardsImpl();
    List<Card> pileOne=new ArrayList<>();
    List<Card> pileTwo=new ArrayList<>();
    if (opponent.choose(Outcome.Neutral,pile2,target,game)) {
      List<UUID> targets=target.getTargets();
      for (      UUID targetId : targets) {
        Card card=pile2.get(targetId,game);
        if (card != null) {
          pile1.add(card);
          pile2.remove(card);
        }
      }
    }
    for (    UUID cardID : pile1) {
      Card card=pile1.get(cardID,game);
      pileOne.add(card);
    }
    for (    UUID cardId : pile2) {
      Card card=pile2.get(cardId,game);
      pileTwo.add(card);
    }
    you.revealCards("String_Node_Str",pile1,game);
    you.revealCards("String_Node_Str",pile2,game);
    boolean choice=you.choosePile(Outcome.PlayForFree,"String_Node_Str",pileOne,pileTwo,game);
    if (choice) {
      game.informPlayer(you,you.getName() + "String_Node_Str");
      while (!pileOne.isEmpty() && you.chooseUse(Outcome.PlayForFree,"String_Node_Str",game)) {
        TargetCard targetExiledCard=new TargetCard(Zone.EXILED,new FilterCard());
        if (you.chooseTarget(Outcome.PlayForFree,pile1,targetExiledCard,source,game)) {
          Card card=pile1.get(targetExiledCard.getFirstTarget(),game);
          if (card != null) {
            if (card.getCardType().contains(CardType.LAND)) {
              you.playLand(card,game);
              pileOne.remove(card);
              pile1.remove(card);
            }
 else {
              you.cast(card.getSpellAbility(),game,true);
              pileOne.remove(card);
              pile1.remove(card);
            }
          }
        }
      }
    }
 else {
      game.informPlayer(you,you.getName() + "String_Node_Str");
      while (!pileTwo.isEmpty() && you.chooseUse(Outcome.PlayForFree,"String_Node_Str",game)) {
        TargetCard targetExiledCard=new TargetCard(Zone.EXILED,new FilterCard());
        if (you.chooseTarget(Outcome.PlayForFree,pile2,targetExiledCard,source,game)) {
          Card card=pile2.get(targetExiledCard.getFirstTarget(),game);
          if (card != null) {
            if (card.getCardType().contains(CardType.LAND)) {
              you.playLand(card,game);
              pileTwo.remove(card);
              pile2.remove(card);
            }
 else {
              you.cast(card.getSpellAbility(),game,true);
              pileTwo.remove(card);
              pile2.remove(card);
            }
          }
        }
      }
    }
    return true;
  }
  return false;
}