<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_unwrapped(self, root, refobjinter):
 """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 """

        all_refobjs = set(refobjinter.get_all_refobjs())
        wrapped = set(root._parentsearchdict.keys())
        return all_refobjs - wrapped