my $t = Transaction->new($dbh);
$t->transaction(sub {
    for (1..10) {
        my $sth = $dbh->prepare(...);
        $sth->execute() or $t->rollback;
    }
});

##</code><code>##

transaction_select $dbh;
transaction {
    for (1..10) {
        my $sth = $dbh->prepare(...);
        $sth->execute() or rollback;
    }
};