Create the generic item, without the render trait. Every property which is not given gets its default. The given
object is completed and returned (it is not copied). Children which are plain objects are completed the same way, all
the way down; a child which already has a has map is taken to be complete and is left alone.
Create the generic item, without the render trait. Every property which is not given gets its default. The given object is completed and returned (it is not copied). Children which are plain objects are completed the same way, all the way down; a child which already has a has map is taken to be complete and is left alone.