package Animal;
use Moose;
sub speak {
    my $self = shift;
    print 'A ', ref $self, ' goes ', $self->sound() . "\n";
}
1;

package Danger;
use Moose;
sub speak {
    my $self = shift;
    print 'through an eye patch ...' . "\n";
}
1;

package Mouse;
use Moose;
extends qw(Animal Danger);
has 'sound' => (is => 'rw', default => 'squeek');
after 'speak' => sub {
    my $self = shift;
    print '[but you can barely hear it!]' . "\n";
};
1;

package main;
my $danger_mouse = Mouse->new();
$danger_mouse->speak();
1;