@Contract("null -> false")
  public static boolean isValidJdk(@Nullable Sdk jdk) {
    if (jdk == null) return false;
    if (!(jdk.getSdkType() instanceof JavaSdkType)) return false;
    if (SdkDownloadTracker.getInstance().isDownloading(jdk)) return true;
    return isValidJdk(jdk.getHomePath());
  }
@Contract("null -> false")
  public static boolean isValidJdk(@Nullable Sdk jdk)