func (tx *Tx) OnRollback(f func(error)) {
	tx.mu.Lock()
	defer tx.mu.Unlock()
	tx.onRollback = append(tx.onRollback, f)
}
// OnRollback adds a function to call on rollback.
OnRollback adds a function to call on rollback.
// OnRollback adds a function to call on rollback .
func (tx *Tx) OnRollback(f func(error)) {
	tx.mu.Lock()
	defer tx.mu.Unlock()
	tx.onRollback = append(tx.onRollback, f)
}
func ( tx * Tx ) OnRollback ( f func ( error ) ) { tx . mu . Lock ( ) defer tx . mu . Unlock ( ) tx . onRollback = append ( tx . onRollback , f ) }
OnRollback adds a function to call on rollback.
OnRollback adds a function to call on rollback .