@Override
  public @Nullable Pair<TextRange, String> getErrorForStringFragment(Pair<TextRange, String> fragment, JsonStringLiteral stringLiteral) {
    String fragmentText = fragment.second;
    if (fragmentText.startsWith("\\") && fragmentText.length() > 1 && fragmentText.endsWith("\n")) {
      if (StringUtil.isEmptyOrSpaces(fragmentText.substring(1, fragmentText.length() - 1))) {
        return null;
      }
    }

    if (fragmentText.startsWith("\\x") && VALID_HEX_ESCAPE.matcher(fragmentText).matches()) {
      return null;
    }

    if (!StandardJsonLiteralChecker.VALID_ESCAPE.matcher(fragmentText).matches() && !INVALID_NUMERIC_ESCAPE.matcher(fragmentText).matches()) {
      return null;
    }

    final String error = StandardJsonLiteralChecker.getStringError(fragmentText);
    return error == null ? null : Pair.create(fragment.first, error);
  }
@Override
  public @Nullable Pair<TextRange, String> getErrorForStringFragment(Pair<TextRange, String> fragment, JsonStringLiteral stringLiteral)