public static @NotNull VirtualFile getSdkRootVirtualFile(@NotNull VirtualFile path) {
    String suffix = path.getExtension();
    if (suffix != null) {
      suffix = StringUtil.toLowerCase(suffix); // Why on earth empty suffix is null and not ""?
    }
    if (!path.isDirectory() && ("zip".equals(suffix) || "egg".equals(suffix))) {
      // a .zip / .egg file must have its root extracted first
      final VirtualFile jar = JarFileSystem.getInstance().getJarRootForLocalFile(path);
      if (jar != null) {
        return jar;
      }
    }
    return path;
  }
public static @NotNull VirtualFile getSdkRootVirtualFile(@NotNull VirtualFile path)