public @Nullable PasswordAuthentication getProxyAuthentication(@NotNull Url repositoryUrl) {
    Proxy proxy = getIdeaDefinedProxy(repositoryUrl);
    PasswordAuthentication result = null;

    if (proxy != null) {
      if (myProxyCredentialsWereReturned) {
        showFailedAuthenticateProxy();
      }
      else {
        result = getProxyAuthentication(proxy, repositoryUrl);
        myProxyCredentialsWereReturned = result != null;
      }
    }

    return result;
  }
public @Nullable PasswordAuthentication getProxyAuthentication(@NotNull Url repositoryUrl)