This example shows cached data eviction. Use eviction to keep a region size
in check when you can easily get the data again from an outside source. If
you have data that is hard to retrieve again, you might want to use data
overflow. (See the DataOverflow example.) The mechanism for deciding when and
what to remove from memory is the same for overflow and standard eviction.
Standard eviction just destroys the entry instead of copying it out to disk.
Both use a Least Recently Used (LRU) eviction controller to decide what to
remove from memory. Please refer to the quickstart guide for instructions on
how to run this example.