@Override
  public void applyFix(@NotNull Project project, @NotNull PsiElement element, @NotNull ModPsiUpdater updater) {
    if (element instanceof PyStringLiteralExpression && element.isWritable()) {
      PyElementGenerator elementGenerator = PyElementGenerator.getInstance(project);

      String stringText = element.getText();
      int prefixLength = PyStringLiteralUtil.getPrefixLength(stringText);
      String prefix = stringText.substring(0, prefixLength);
      String content = stringText.substring(prefixLength);
      if (content.startsWith("'''") ) {
        content = content.substring(3, content.length()-3);
      } else if (content.startsWith("\"\"\""))
        return;
      else {
        content = content.length() == 1 ? "" : content.substring(1, content.length()-1);
      }
      if (content.endsWith("\""))
        content = StringUtil.replaceSubstring(content, TextRange.create(content.length()-1, content.length()), "\\\"");

      PyExpression newString = elementGenerator.createDocstring(prefix+"\"\"\"" + content + "\"\"\"").getExpression();
      element.replace(newString);
    }
  }
@Override
  public void applyFix(@NotNull Project project, @NotNull PsiElement element, @NotNull ModPsiUpdater updater)