use feature "state";
use strict;
use warnings FATAL => qw(all);
use Type::Params qw(compile);
use Types::Standard qw(Object);
use Types::Common::Numeric qw(PositiveOrZeroInt);

sub set_age {
  state $check = compile(Object, PositiveOrZeroInt);
  my ($self, $age) = $check->(@_);
  $self->{age} = $age;
  return $self;
}