package Foo;
use Bar;

sub new {
    return bless {}, shift;
}

1;
##</code><code>##

package Bar;
use Foo;

sub new {
    return bless {}, shift;
}

my $foo = Foo->new();

1;
##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;

use Foo;