val books: List[Book] = Books.all  //Book is MappedOneToMany Object

books match {

    case Nil => "was an empty list"

    case x :: xs => {

      object book extends ScreenVar(xs)

      addFields(() => book) // error: type mismatch;
//[INFO]  found   : book.type (with underlying type object up)
//[INFO]  required: net.liftweb.util.FieldContainer
//[INFO]       addFields(() => book)

    }

  }