my $cube = new Cubicle;
$cube->add(new Coder);
my $thing = $cube->query;

print "\L
$thing->{sound}
comes the sound from a @{[ref($cube)]}.

is it a guinea pig?
@{[ref($thing) eq 'Pig::guinea' ? 'yes' : 'no']}

is it a coder?
@{[ref($thing) eq 'Coder' ? 'yes' : 'no']}

is the coder a guinea pig?
@{[$thing->isa('Pig::guinea') ? 'yes' : 'no']}
";

package Pig::guinea;
sub new {bless{sound=>('ernk 'x3)},shift}

package Coder;
use base Pig::guinea;
sub new {bless{sound=>('tap 'x3)},shift}

package Cubicle;
sub new   {bless{contents=>[]},shift}
sub add   {push @{shift->{contents}},shift}
sub query {pop @{shift->{contents}}}
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