my $artist = Artist->new_result({
    name => "John",
    artist_cd_rs => [
      {cd => {title=>"one"}},
      {cd => {title=>"two"}},
    ],
});

ok $artist->custom_method_on_resultsourc;


$artist->artist_cd_rs->first->cd->title; # !!! This explodes

ok $artist->insert_or_update;