Multiple checkboxes to Collection mapping

Using Spring's <form:checkboxes> tag to present multiple checkboxes for the user to choose values of a collection attribute of the model (e.g. Set<T>) WebFlow only offers the first selected value for mapping, and requests it to be mapped as a collection (Set, List, etc). The subsequent values are discarded silently.
Expected behavior would be convert every individual value to type T and set the attribute as the collection (e.g. Set<T>)
Spring MVC works this way.

Reference: http://forum.springframework.org/showthread.php?p=183366