The collection of the IterableEntity or Iterable2Entity can hold nullable modddels. For example :
/// ListEntity example
//...
factory TodoList({
required List<Todo?> todos,
}) //...
/// MapEntity example
//...
factory BookMap({
required Map<Author, Book?> booksByAuthors,
}) //...
If a modddel is null, it is considered valid during the contentValidationStep.
If you want a nullable modddel to cause a failure when it's null, you should use .
