use strict;
use warnings;

package PrintMe;

sub AsStr {
    my ($self) = @_;

    return $self->{str};
};

sub new {
    my ($class, $str) = @_;

    return bless {str => $str}, $class;
}

package PrintMeToo;

use base 'PrintMe';

sub AsStr {
    my ($self) = @_;

    return 'Me too: ' . $self->SUPER::AsStr();
};

package main;

my $meToo = PrintMeToo->new('This string');

print $meToo->AsStr();