code: def get_unwrapped(self, root, refobjinter):
          
          all_refobjs = set(refobjinter.get_all_refobjs())
          wrapped = set(root._parentsearchdict.keys())
          return all_refobjs - wrapped
docs: Return a set with all refobjects in the scene that are not in already
          wrapped in root.
  
          :param root: the root that groups all reftracks and makes it possible to search for parents
          :type root: :class:`ReftrackRoot`
          :param refobjinter: a programm specific reftrack object interface
          :type refobjinter: :class:`RefobjInterface`
          :returns: a set with unwrapped refobjects
          :rtype: set
          :raises: None