8 threads x 60000 ops (80% get / 20% put), capacity 64, 256 keys
================================================================

implementation           exceptions   wrong values   size>capacity seen?    invariants       post-stress LRU check
SynchronizedLruCache     0            0              no                     ok               ok
ReentrantLockLruCache    0            0              no                     ok               ok
StripedLruCache(8)       0            0              no                     ok               n/a (per-segment LRU)

Hit/miss counts are deliberately not printed: they differ on every run and nothing asserts them.
