private void registerErrorInString(@NotNull PsiLiteralExpression expression) {
      final String text = expression.getText();
      final int[] offsets = new int[text.length() + 1];
      final CharSequence result = CodeInsightUtilCore.parseStringCharacters(text, offsets);
      if (result == null) {
        return;
      }
      for (int i = 0, length = result.length(); i < length; i++) {
        final char c = result.charAt(i);
        if (c == SLASH || c == BACKSLASH) {
          registerErrorAtOffset(expression, offsets[i], offsets[i + 1] - offsets[i]);
        }
      }
    }
private void registerErrorInString(@NotNull PsiLiteralExpression expression)