code: func (t *InjectedTransaction) Commit(ctx context.Context) error {
  	t.cfg.RLock()
  	defer t.cfg.RUnlock()
  	if t.cfg.commitError != nil {
  		return t.cfg.commitError
  	}
  	return t.Transaction.Commit(ctx)
  }
docs: // Commit returns an error if cfg.commitError is set.