class MongoEventLog implements LotteryEventLog {

  private static final String DEFAULT_DB = "lotteryDB";
  private static final String DEFAULT_EVENTS_COLLECTION = "events";
  private static final String EMAIL = "email";
  private static final String PHONE = "phone";
  public static final String MESSAGE = "message";

  private MongoClient mongoClient;
  private MongoDatabase database;
  private MongoCollection<Document> eventsCollection;

  private final StdOutEventLog stdOutEventLog = new StdOutEventLog();

  /**
   * Constructor.
   */
  public MongoEventLog() {
    connect();
  }

  /**
   * Constructor accepting parameters.
   */
  public MongoEventLog(String dbName, String eventsCollectionName) {
    connect(dbName, eventsCollectionName);
  }

  /**
   * Connect to database with default parameters.
   */
  public void connect() {
    connect(DEFAULT_DB, DEFAULT_EVENTS_COLLECTION);
  }

  /**
   * Connect to database with given parameters.
   */
  public void connect(String dbName, String eventsCollectionName) {
    if (mongoClient != null) {
      mongoClient.close();
    }
    mongoClient = new MongoClient(System.getProperty("mongo-host"),
        Integer.parseInt(System.getProperty("mongo-port")));
    database = mongoClient.getDatabase(dbName);
    eventsCollection = database.getCollection(eventsCollectionName);
  }

  /**
   * Get mongo client.
   *
   * @return mongo client
   */
  public MongoClient getMongoClient() {
    return mongoClient;
  }

  /**
   * Get mongo database.
   *
   * @return mongo database
   */
  public MongoDatabase getMongoDatabase() {
    return database;
  }

  /**
   * Get events collection.
   *
   * @return events collection
   */
  public MongoCollection<Document> getEventsCollection() {
    return eventsCollection;
  }


  @Override
  public void ticketSubmitted(PlayerDetails details) {<FILL_FUNCTION_BODY>}

  @Override
  public void ticketSubmitError(PlayerDetails details) {
    var document = new Document(EMAIL, details.getEmail());
    document.put(PHONE, details.getPhoneNumber());
    document.put("bank", details.getBankAccount());
    document.put(MESSAGE, "Lottery ticket could not be submitted because lack of funds.");
    eventsCollection.insertOne(document);
    stdOutEventLog.ticketSubmitError(details);
  }

  @Override
  public void ticketDidNotWin(PlayerDetails details) {
    var document = new Document(EMAIL, details.getEmail());
    document.put(PHONE, details.getPhoneNumber());
    document.put("bank", details.getBankAccount());
    document.put(MESSAGE, "Lottery ticket was checked and unfortunately did not win this time.");
    eventsCollection.insertOne(document);
    stdOutEventLog.ticketDidNotWin(details);
  }

  @Override
  public void ticketWon(PlayerDetails details, int prizeAmount) {
    var document = new Document(EMAIL, details.getEmail());
    document.put(PHONE, details.getPhoneNumber());
    document.put("bank", details.getBankAccount());
    document.put(MESSAGE, String
        .format("Lottery ticket won! The bank account was deposited with %d credits.",
            prizeAmount));
    eventsCollection.insertOne(document);
    stdOutEventLog.ticketWon(details, prizeAmount);
  }

  @Override
  public void prizeError(PlayerDetails details, int prizeAmount) {
    var document = new Document(EMAIL, details.getEmail());
    document.put(PHONE, details.getPhoneNumber());
    document.put("bank", details.getBankAccount());
    document.put(MESSAGE, String
        .format("Lottery ticket won! Unfortunately the bank credit transfer of %d failed.",
            prizeAmount));
    eventsCollection.insertOne(document);
    stdOutEventLog.prizeError(details, prizeAmount);
  }
}

    var document = new Document(EMAIL, details.getEmail());
    document.put(PHONE, details.getPhoneNumber());
    document.put("bank", details.getBankAccount());
    document
        .put(MESSAGE, "Lottery ticket was submitted and bank account was charged for 3 credits.");
    eventsCollection.insertOne(document);
    stdOutEventLog.ticketSubmitted(details);
  
<no_super_class>