Admin_ObjectController::detectDeletedRemoteOwnerRelations PHP Method

    protected function detectDeletedRemoteOwnerRelations($relations, $value)
    {
        $originals = [];
        $changed = [];
        foreach ($relations as $r) {
            $originals[] = $r["dest_id"];
        }
        if (is_array($value)) {
            foreach ($value as $row) {
                $changed[] = $row['id'];
            }
        }
        $diff = array_diff($originals, $changed);
        return $diff;
    }