//1. use in your structs
type User struct {
	Name    string             `json:"name" db:"name"`
	Country country.Alpha2Code `json:"country" db:"country"`
}
func main() {
	user := User{}
	//2. use in your wire
	json.Unmarshal([]byte(`{"name":"name", "country": "ca"}`), &user)
	//3. check is set
	user.Country.IsSet() //check user country is provided
	//4. validate using ozzo-validation
	if err := validation.ValidateStruct(&user, validation.Field(&user.Country, validation.Required, user.Country)); err != nil {
		log.Fatal(err)
	}
	//5. lookup by alpha2, alpha3, country name
	if userCountry, ok := country.ByAlpha2Code(user.Country); ok {
		fmt.Printf("country name - '%s', alpha-2 - '%s', alpha-3 - '%s'", userCountry.Name(), userCountry.Alpha2Code(), userCountry.Alpha3Code())
	}
	//6. store in db
	fmt.Println(user.Country.Value()) //prints 'CA'
	//7. use specific countries
	fmt.Println(country.Canada.Alpha2Code())
}

country.ByNameStrErr()
country.ByNameErr()
country.ByNameStr()
country.ByName()
country.ByAlpha2CodeStrErr()
country.ByAlpha2CodeErr()
country.ByAlpha2CodeStr()
country.ByAlpha2Code()
country.ByAlpha3CodeStrErr()
country.ByAlpha3CodeErr()
country.ByAlpha3CodeStr()
country.ByAlpha3Code()

...
country.Canada
country.Alpha2CA
country.Alpha3CAN
country.NameCanada
...

type Country struct {
    name   Name
    alpha2 Alpha2Code
    alpha3 Alpha3Code
}
func (c Country) Name() Name             { return c.name }
func (c Country) Alpha2Code() Alpha2Code { return c.alpha2 }
func (c Country) Alpha3Code() Alpha3Code { return c.alpha3 }
func (c Country) NameStr() string        { return c.name.String() }
func (c Country) Alpha2CodeStr() string  { return c.alpha2.String() }
func (c Country) Alpha3CodeStr() string  { return c.alpha3.String() }