ullable
  public static String getOnlyUrlFor(PsiElement element, PsiElement originalElement) {
    PsiFileSystemItem file = getFile(element);
    if (file == null) return null;
    final Sdk sdk = PyBuiltinCache.findSdkForFile(file);
    if (sdk == null) {
      return null;
    }
    final QualifiedName qName = QualifiedNameFinder.findCanonicalImportPath(element, originalElement);
    if (qName == null) {
      return null;
    }
    final PythonDocumentationMap map = PythonDocumentationMap.getInstance();
    final String pyVersion = pyVersion(sdk.getVersionString());
    PsiNamedElement namedElement = getNamedElement(element);
    final String url = map.urlFor(qName, namedElement, pyVersion);
    if (url != null) {
      return url;
    }
    for (PythonDocumentationLinkProvider provider : PythonDocumentationLinkProvider.EP_NAME.getExtensionList()) {
      final String providerUrl = provider.getExternalDocumentationUrl(element, originalElement);
      if (providerUrl != null) {
        return providerUrl;
      }
    }
    return null;
  }


ullable
  public static String getOnlyUrlFor(PsiElement element, PsiElement originalElement) {