private void dumpSurvivalData(Map<String, List<SurvivalData>> survivalData) {
    List<String> daysToDeath = new ArrayList<String>();
    List<String> lastFollowUp = new ArrayList<String>();
    List<String> lastKnownAlive = new ArrayList<String>();
    List<String> vitalStatus = new ArrayList<String>();

    for (String patientId : new TreeSet<String>(survivalData.keySet())) {
      for (SurvivalData sd : survivalData.get(patientId)) {
        daysToDeath.add(sd.daysToDeath);
        lastFollowUp.add(sd.lastFollowUp);
        lastKnownAlive.add(sd.lastKnownAlive);
        vitalStatus.add(sd.vitalStatus);
      }

      System.out.print(patientId + "\t\t");
      printList(daysToDeath);
      printList(lastFollowUp);
      printList(lastKnownAlive);
      printList(vitalStatus);
      System.out.println();

      daysToDeath.clear();
      lastFollowUp.clear();
      lastKnownAlive.clear();
      vitalStatus.clear();
    }
  }
 private List<String> initializeList(int size) {
   List<String> os = new ArrayList<String>(size);
   for (int lc = 0; lc < size; lc++) {
     os.add(lc, "");
   }
   return os;
 }
  private List<String> convertFollowupPatientIds(List<String> patientIds) {
    List<String> convertedPatientIds = new ArrayList<String>();

    for (String patientId : patientIds) {
      Matcher patientIdMatcher = FOLLOW_UP_PATIENT_ID_REGEX.matcher(patientId);
      convertedPatientIds.add(patientIdMatcher.find() ? patientIdMatcher.group(1) : patientId);
    }

    return convertedPatientIds;
  }