view release on metacpan or  search on metacpan

t/005_order_disagreement.t  view on Meta::CPAN

    package Z;
    our @ISA = ('XY', 'YX');
}

eval {
    Algorithm::C3::merge('Z' => sub {
        no strict 'refs';
        @{$_[0] . '::ISA'};
    })
};
like($@, qr/^Inconsistent hierarchy/, '... got the right error with an inconsistent hierarchy');