public void onUnhandledException(Request request) {
        metric.add(ContainerMetrics.JDISC_HTTP_HANDLER_UNHANDLED_EXCEPTIONS.baseName(), 1, contextFor(request));
    }
Common HTTP request handler metrics code.

@author jonmv
@author bjorncs
container-core/src/main/java/com/yahoo/container/core/HandlerMetricContextUtil.java