private void convertNanosToDuration(final Map<String, String> map,
                                        final String k,
                                        final String v) {
        try {
            final long nanos = Long.parseLong(v);
            map.put(k, ModelStringUtil.formatDurationString(
                    nanos / 1_000_000, true));

        } catch (final RuntimeException e) {
            // Ignore.
        }
    }
Subclasses should implement this method to add to the cacheBuilder as required
and return a cache built from cacheBuilder. The builder already has a
removalNotificationConsumer if applicable and recordStats has been set.
stroom-cache/stroom-cache-impl/src/main/java/stroom/cache/impl/AbstractStroomCache.java