private static @Nullable SystemFileTypeAssociator createAssociator() {
    if (SystemInfo.isLinux) {
      return new LinuxFileTypeAssociator();
    }
    if (SystemInfo.isWindows) {
      return new WinFileTypeAssociator();
    }
    if (SystemInfo.isMac) {
      return new MacOSFileTypeAssociator();
    }
    return null;
  }
private static @Nullable SystemFileTypeAssociator createAssociator()