default @Nls @Nullable String fetchExternalDocumentation(final Project project, PsiElement element, List<String> docUrls, boolean onHover) {
    return fetchExternalDocumentation(project, element, docUrls);
  }
default @Nls @Nullable String fetchExternalDocumentation(final Project project, PsiElement element, List<String> docUrls, boolean onHover)