# File test_v1.pm
use strict;
use warnings;

package Foo;

sub new {
   my $class = shift;
   bless { version => 1 }, $class;
}

sub version {
    my $self = shift;
    return $self->{version};
}

package Foo::Bar;

use parent -norequire, 'Foo';

1;

##</code><code>##

# File test_v2.pm
use strict;
use warnings;

package Foo;

sub new {
   my $class = shift;
   bless { version => 2 }, $class;
}

sub version {
    my $self = shift;
    return $self->{version};
}

package Foo::Bar;

use parent -norequire, 'Foo';

1;