Challenge 3: Extend with SUPER:: — Possible Solution
====================================================================

package Animal;
sub new   { my ($class, $name) = @_; return bless { name => $name }, $class; }
sub speak { my $self = shift; return "$self->{name} makes a sound"; }

package Dog;
our @ISA = ('Animal');
sub speak { my $self = shift; return "$self->{name} says Woof!"; }

package LoudDog;
our @ISA = ('Dog');

sub speak {
    my $self = shift;
    my $base = $self->SUPER::speak();
    return "$base (LOUDLY)";
}

package main;
use strict;
use warnings;
use feature 'say';

my $dog = LoudDog->new("Rex");
say $dog->speak();

Output:
Rex says Woof! (LOUDLY)

WHY THIS WORKS AS AN ANSWER
------------------------------
Animal and Dog are reused completely unchanged from the chapter's own
worked example — Dog's speak() already overrides Animal's, per the
chapter's own explanation of method resolution walking @ISA.

package LoudDog; our @ISA = ('Dog'); reuses the chapter's own @ISA
inheritance syntax, this time chaining a THIRD level — LoudDog
inherits from Dog, which itself inherits from Animal — demonstrating
that @ISA chains work through multiple levels, not just one.

$self->SUPER::speak(); reuses the chapter's own SUPER:: syntax
exactly. Critically, per the chapter's own explanation, SUPER::
resolves relative to the CURRENT package (LoudDog), so it calls Dog's
speak() — the nearest parent's version — not Animal's, even though
Animal also has a speak(). This is what returns "Rex says Woof!" as
$base, rather than "Rex makes a sound".

return "$base (LOUDLY)"; then extends rather than replaces that
inherited behavior, reusing string interpolation (Course 1, Chapter
2) to append the extra text — precisely the "extending, rather than
fully replacing, inherited behavior" use case the chapter names
SUPER:: as being for.