code: func TxidVisibleInSnapshot(db XODB, v0 int64, v1 pgtypes.TxidSnapshot) (bool, error) {
  	var err error
  
  	// sql query
  	const sqlstr = `SELECT pg_catalog.txid_visible_in_snapshot($1, $2)`
  
  	// run query
  	var ret bool
  	XOLog(sqlstr, v0, v1)
  	err = db.QueryRow(sqlstr, v0, v1).Scan(&ret)
  	if err != nil {
  		return false, err
  	}
  
  	return ret, nil
  }
docs: // TxidVisibleInSnapshot calls the stored procedure 'pg_catalog.txid_visible_in_snapshot(bigint, txid_snapshot) boolean' on db.