package City;
use Moose;

has temperature => (
  traits => ['Cache'],
  is => 'rw',
  isa => 'Int',
  builder => _get_temperature,
  required => 1,
  expiration_time => 10,
);

sub _get_temperature {
  state $t = 10;
  return $t++;
}

no Moose;
1;

package main;
my $city = City->new();

say $city->temperature() # 10
# after +10 seconds
say $city->temperature() # 11
# after +10 seconds
say $city->temperature() # 12