perl -MMemoize -MMemoize::Expire -E 
  "sub f {int rand 100};
   tie my %cache => 'Memoize::Expire',LIFETIME=>2; 
   memoize 'f',SCALAR_CACHE => [HASH => \%cache ];
   for (1..10) {print f().$/; sleep 1}"
16
16
95
95
61
61
62
62
93
93

perl -MMemoize -MMemoize::Expire -E 
  "sub f {int rand 100};
   tie my %cache => 'Memoize::Expire',LIFETIME=>2; 
   memoize 'f',SCALAR_CACHE => [HASH => \%cache ];
   for (1..10) {say f(); sleep 1}"
89
89
89
89
89
89
89
89
89
89