code: func (t *Transaction) Commit() error {
  	if !t.closed {
  		t.closed = true
  		if t.dbmap.logger != nil {
  			now := time.Now()
  			defer t.dbmap.trace(now, "commit;")
  		}
  		return t.tx.Commit()
  	}
  
  	return sql.ErrTxDone
  }
docs: // Commit commits the underlying database transaction.