SERVER-92699 is introducing new functionality to evict elements of a ReadThroughCache based on a "not accessed since X time ago" policy. The execution of this cleanup routine is expected to add latency to concurrent read/write accesses to the cached elements: the objective of this ticket is to define a benchmark to access the order of magnitude of this contribution against a "worst case scenario" (a full ReadThroughCache configured with the maximum custom capacity possible, where all of its entries have to be evicted according to the policy).