public Date getPreferencesDate() {
   String username = getUsername();
   try {
     UserPreferences userPreferences =
         (UserPreferences) storageService.getEntity(UserPreferences.getPath(username));
     return userPreferences.getCreatedDate();
   } catch (NotFoundException e) {
     return new Date();
   }
 }
 public Map<String, String> getPreferences() {
   String username = getUsername();
   try {
     UserPreferences userPreferences =
         (UserPreferences) storageService.getEntity(UserPreferences.getPath(username));
     return userPreferences.getPreferences();
   } catch (NotFoundException e) {
     return new HashMap<String, String>();
   }
 }
  public void setPreferences(Map<String, String> preferences) {
    String username = SecurityUtil.getLoggedUsername();
    UserPreferences userPreferences;
    try {
      userPreferences =
          (UserPreferences) storageService.getEntity(UserPreferences.getPath(username));
    } catch (NotFoundException e) {
      userPreferences = new UserPreferences(username);
    }

    userPreferences.setPreferences(preferences);
    storageService.addOrModifyEntity(userPreferences);
  }