Pool: shrink now works with n > 1
Pool: shrink now works with n > 1

jakirkham/billiard,jakirkham/billiard,pombredanne/billiard,flaviogrossi/billiard,djsmith42/billiard,djsmith42/billiard,andresriancho/billiard,flaviogrossi/billiard,pombredanne/billiard,andresriancho/billiard