Program: 117592
Project: 117592
Buggy source:
public static void main(final String[] args){
  final Summoner summoner=Summoner.withAccountId(36321079).withRegion(Region.NORTH_AMERICA).get();
  final MatchHistory matchHistory=MatchHistory.forSummoner(summoner).get();
  final Map<Integer,String> championIdToNameMapping=new HashMap<>();
  for (  final Champion champion : Champions.withRegion(Region.NORTH_AMERICA).get()) {
    championIdToNameMapping.put(champion.getId(),champion.getName());
  }
  final Map<String,Integer> playedChampions=new HashMap<>();
  for (  final Match match : matchHistory) {
    final Integer championId=match.getParticipants().find(summoner).getChampion().getId();
    final String championName=championIdToNameMapping.get(championId);
    Integer count=playedChampions.get(championName);
    if (count == null) {
      count=0;
      playedChampions.put(championName,count);
    }
    playedChampions.put(championName,playedChampions.get(championName) + 1);
  }
  System.out.println("String_Node_Str" + matchHistory.size());
  playedChampions.entrySet().stream().sorted(Map.Entry.comparingByValue()).collect(Collectors.toMap(Map.Entry::getKey,Map.Entry::getValue,(e1,e2) -> e1,LinkedHashMap::new));
  System.out.println("String_Node_Str" + summoner.getName() + "String_Node_Str");
  for (  final String championName : playedChampions.keySet()) {
    final Integer count=playedChampions.get(championName);
    System.out.println(championName + "String_Node_Str" + count);
  }
  System.out.println("String_Node_Str");
  final Match match=matchHistory.get(0);
  System.out.println("String_Node_Str" + match.getId());
  final Participant participant=match.getParticipants().find(summoner);
  System.out.println("String_Node_Str");
  System.out.println(participant.getSummoner().getName() + "String_Node_Str" + participant.getChampion().getName());
  System.out.println("String_Node_Str");
  for (  final Participant p : match.getParticipants()) {
    System.out.println(p.getSummoner().getName() + "String_Node_Str" + p.getChampion().getName());
  }
  System.out.println("String_Node_Str");
  for (  final Participant p : match.getParticipants()) {
    System.out.println(p.getSummoner().getName() + "String_Node_Str" + p.getChampion().getName());
  }
  System.out.println("String_Node_Str" + match.getBlueTeam().isWinner());
  System.out.println("String_Node_Str" + match.getRedTeam().isWinner());
  System.out.println("String_Node_Str");
  for (  final Participant p : match.getBlueTeam().getParticipants()) {
    System.out.println(p.getSummoner().getName());
  }
}

Fixed version (ground truth):
public static void main(final String[] args){
  final Summoner summoner=Summoner.withAccountId(36321079).withRegion(Region.NORTH_AMERICA).get();
  final MatchHistory matchHistory=MatchHistory.forSummoner(summoner).get();
  final Map<Integer,String> championIdToNameMapping=new HashMap<>();
  for (  final Champion champion : Champions.withRegion(Region.NORTH_AMERICA).get()) {
    championIdToNameMapping.put(champion.getId(),champion.getName());
  }
  final Map<String,Integer> playedChampions=new HashMap<>();
  for (  final Match match : matchHistory) {
    final Integer championId=match.getParticipants().find(summoner).getChampion().getId();
    final String championName=championIdToNameMapping.get(championId);
    Integer count=playedChampions.get(championName);
    if (count == null) {
      count=0;
      playedChampions.put(championName,count);
    }
    playedChampions.put(championName,playedChampions.get(championName) + 1);
  }
  System.out.println("String_Node_Str" + matchHistory.size());
  List<Entry<String,Integer>> entries=new ArrayList<>(playedChampions.entrySet());
  entries.sort((  Entry<String,Integer> e0,  Entry<String,Integer> e1) -> Integer.compare(e1.getValue(),e0.getValue()));
  for (int i=0; i < 10 && i < entries.size(); i++) {
    String championName=entries.get(i).getKey();
    int count=entries.get(i).getValue();
    System.out.println(championName + "String_Node_Str" + count);
  }
  System.out.println("String_Node_Str");
  final Match match=matchHistory.get(0);
  System.out.println("String_Node_Str" + match.getId());
  final Participant participant=match.getParticipants().find(summoner);
  System.out.println("String_Node_Str");
  System.out.println(participant.getSummoner().getName() + "String_Node_Str" + participant.getChampion().getName());
  System.out.println("String_Node_Str");
  for (  final Participant p : match.getParticipants()) {
    System.out.println(p.getSummoner().getName() + "String_Node_Str" + p.getChampion().getName());
  }
  System.out.println("String_Node_Str");
  for (  final Participant p : match.getParticipants()) {
    System.out.println(p.getSummoner().getName() + "String_Node_Str" + p.getChampion().getName());
  }
  System.out.println("String_Node_Str" + match.getBlueTeam().isWinner());
  System.out.println("String_Node_Str" + match.getRedTeam().isWinner());
  System.out.println("String_Node_Str");
  for (  final Participant p : match.getBlueTeam().getParticipants()) {
    System.out.println(p.getSummoner().getName());
  }
}