private static boolean isRootInExistingFile(VirtualFile root) {
    if (root.getFileSystem() instanceof JarFileSystem) {
      VirtualFile jar = JarFileSystem.getInstance().getVirtualFileForJar(root);
      // we might be invoked outside EDT, so sync VFS refresh is impossible, so we check java.io.File existence
      if (jar == null || !VfsUtilCore.virtualToIoFile(jar).exists()) return false;
    }

    return true;
  }
private static boolean isRootInExistingFile(VirtualFile root)