SealedEmailWithFactory.kt

sealed class Email(val value: String){
    data class Verified(private val email: Unverified): Email(email.value)
    class Unverified private constructor(value: String): Email(value){
        companion object{
            fun of(value: String): Result<Email.Unverified> = valikate {
                validate(Email.Unverified(value)){
                    validate(Email.Unverified::value).isEmail()
                }
            }
        }
    }
}