#!/usr/bin/perl

use warnings;
use strict;

package Box {

    sub new {
        my $classname = shift;
        my $content_at_beginning = shift;
        my $self = {content => $content_at_beginning};
        return bless($self, $classname);
    }
}

my $box1 = Box->new(1);
my $box2 = Box->new(5);