protected WhereisHelper getHelper() {
    OsEnum os = OsEnum.getOS(System.getProperty("os.name"));
    switch (os) {
      case WINDOWS_XP:
      case WINDOWS_VISTA:
      case WINDOWS_SEVEN:
        return new WhereisStubHelper();
      case LINUX:
      case MAC_OSX:
        return new WhereisHelper();
      default:
        return new WhereisHelper();
    }
  }