The statistics class provides information about one or more Set that
is not readily available because expensive to compute or provided by a
remote source.
The class provides also facilities to work with a collection of sets. It always caches in memory the computed values and it can take an optional path to cache file that it is responsible of populating and invalidating.
To reuse the in memory cache and to minimize the disk access to the cache file a shared instance is also available.
Object