code: func AuthGroupPermissionByID(db XODB, id int) (*AuthGroupPermission, error) {
  	var err error
  
  	// sql query
  	const sqlstr = `SELECT ` +
  		`id, group_id, permission_id ` +
  		`FROM public.auth_group_permissions ` +
  		`WHERE id = $1`
  
  	// run query
  	XOLog(sqlstr, id)
  	agp := AuthGroupPermission{
  		_exists: true,
  	}
  
  	err = db.QueryRow(sqlstr, id).Scan(&agp.ID, &agp.GroupID, &agp.PermissionID)
  	if err != nil {
  		return nil, err
  	}
  
  	return &agp, nil
  }
docs: // AuthGroupPermissionByID retrieves a row from 'public.auth_group_permissions' as a AuthGroupPermission.
  //
  // Generated from index 'auth_group_permissions_pkey'.