private String formatAttributeMapLogging(final AttributeMap attributeMap) {
        return attributeMap
                .entrySet()
                .stream()
                .map(entry -> new SimpleEntry<>(
                        Objects.requireNonNullElse(entry.getKey(), "null"),
                        entry.getValue())
                )
                .sorted(Entry.comparingByKey())
                .map(entry -> "  " + String.join(
                        ":",
                        NullSafe.string(entry.getKey()),
                        LogUtil.truncateUnless(entry.getValue(), 50, LOGGER.isTraceEnabled())))
                .collect(Collectors.joining("\n"));
    }
Handler class that forwards the request to a URL.
stroom-proxy/stroom-proxy-app/src/main/java/stroom/proxy/app/handler/HttpSender.java