private @Nullable Sdk guessJdk() {
    JavaSdk javaSdk = JavaSdk.getInstance();
    List<Sdk> jdks = getSdksOfType(javaSdk);
    if (!jdks.isEmpty()) return null;
    String homePath = ApplicationManager.getApplication().getService(DefaultJdkConfigurator.class).guessJavaHome();
    if (homePath == null || !javaSdk.isValidSdkHome(homePath)) return null;
    String suggestedName = JdkUtil.suggestJdkName(javaSdk.getVersionString(homePath));
    if (suggestedName == null) return null;
    ProgressManager.checkCanceled();
    return javaSdk.createJdk(suggestedName, homePath, false);
  }
private @Nullable Sdk guessJdk()