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: migrator.go
    path of file: ./repos/AdGuardHome/internal/configmigrate
    
    the code of the file until where you have to start completion: package configmigrate

import (
	"bytes"
	"fmt"

	"github.com/AdguardTeam/golibs/log"
	yaml "gopkg.in/yaml.v3"
)

// Config is a the configuration for initializing a [Migrator].
type Config struct {
	// WorkingDir is an absolute path to the working directory of AdGuardHome.
	Wor
    
func validateVersion(current, target uint) (err error) {
	switch {
	case current > target:
		return fmt.Errorf("unknown current schema version %d", current)
	case target > LastSchemaVersion:
		return fmt.Errorf("unknown target schema version %d", target)
	case target < current:
		return fmt.Errorf("target schema version %d lower than current %d", target, current)
	default:
		return nil
	}
}