use strict;
use warnings;

package BaseClass;

sub new {
    return bless {}, shift;
}


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

    return $self->GetX ();
}

1;

package main;

use base 'BaseClass';

my $obj = main->new ();
my $privateX = 42;

print $obj->useVirtualX ();


sub new {
    return shift->SUPER::new ();
}


sub GetX {
    return $privateX;
}

##</code><code>##

42