in elitzur-core/src/main/scala/com/spotify/elitzur/validators/Validator.scala [117:129]
override def validate(
a: PreValidation[Option[A]]
): PostValidation[Option[A]] = {
val option = a.forceGet
if (option.isEmpty) {
Valid(Option.empty)
} else {
implicitly[FieldValidator[A]]
.validate(Unvalidated(option.get))
.map(Option(_))
.asInstanceOf[PostValidation[Option[A]]]
}
}