@Nullable
  public static DocStringFormat getFormatFromDocformatAttribute(@NotNull PsiFile file) {
    if (file instanceof PyAstFile) {
      final PyAstTargetExpression expr = ((PyAstFile)file).findTopLevelAttribute(PyNames.DOCFORMAT);
      if (expr != null) {
        final String docformat = PyPsiUtilsCore.strValue(expr.findAssignedValue());
        if (docformat != null) {
          final List<String> words = StringUtil.split(docformat, " ");
          if (words.size() > 0) {
            final DocStringFormat fileFormat = DocStringFormat.fromName(words.get(0));
            if (fileFormat != null) {
              return fileFormat;
            }
          }
        }
      }
    }
    return null;
  }
@Nullable
  public static DocStringFormat getFormatFromDocformatAttribute(@NotNull PsiFile file)