You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: auniqueindexcomposite.xo.go
    path of file: ./repos/xo/_examples/a_bit_of_everything/postgres
    
    the code of the file until where you have to start completion: package postgres

// Code generated by xo. DO NOT EDIT.

import (
	"context"
	"database/sql"
)

// AUniqueIndexComposite represents a row from 'public.a_unique_index_c
    
func AUniqueIndexCompositeByAKey1AKey2(ctx context.Context, db DB, aKey1, aKey2 sql.NullInt64) (*AUniqueIndexComposite, error) {
	// query
	const sqlstr = `SELECT ` +
		`a_key1, a_key2 ` +
		`FROM public.a_unique_index_composite ` +
		`WHERE a_key1 = $1 AND a_key2 = $2`
	// run
	logf(sqlstr, aKey1, aKey2)
	auic := AUniqueIndexComposite{}
	if err := db.QueryRowContext(ctx, sqlstr, aKey1, aKey2).Scan(&auic.AKey1, &auic.AKey2); err != nil {
		return nil, logerror(err)
	}
	return &auic, nil
}