public Builder maximumSize(final Integer maximumSize) {
            this.maximumSize = NullSafe.get(maximumSize, Integer::longValue);
            return this;
        }
Uses Dropwizard Metrics for capturing statistics. This allows the cache stats
to be accessed via tools such as Graphite/Collectd in addition to the Stroom UI.
This is suitable for both Stroom and Stroom-Proxy.
This adds a very slight performance overhead over {@link StatisticsMode#INTERNAL}.
stroom-util/src/main/java/stroom/util/cache/CacheConfig.java