try (ByteArrayOutputStream baos = new ByteArrayOutputStream();
                PrintWriter writer = new PrintWriter(baos, false, Constants.CHARSET_UTF_8)) {
            exception.printStackTrace(writer);
            writer.flush();
            append(buf, "exception", () -> StringEscapeUtils.escapeJson(new String(baos.toByteArray(), Constants.CHARSET_UTF_8)));
        } catch (final IOException e) {