my $page1 = My::Page->create({ location => 'abc' });
my $page2 = $page1->add_to_inbound({ location => 'def' });

##</code><code>##

my $page1 = My::Page->create({ location => 'abc' });
my $page2 = My::Page->create({ location => 'def' });

My::Link->create({src => $page1, dst => $page2});

croak Dumper([$page1->inbound()],
             [$page1->outbound()],
             [$page2->inbound()],
             [$page2->outbound()],
             );