def set_parent_on_new(self, parentrefobj):
        """Contextmanager that on close will get all new
        unwrapped refobjects, and for every refobject with no parent
        sets is to the given one.

        :returns: None
        :rtype: None
        :raises: None
        """
        refobjinter = self.get_refobjinter()
        # to make sure we only get the new one
        # we get all current unwrapped first
        old = self.get_unwrapped(self.get_root(), refobjinter)
        yield
        new = self.get_unwrapped(self.get_root(), refobjinter) - old
        for refobj in new:
            if refobjinter.get_parent(refobj) is None:
                refobjinter.set_parent(refobj, parentrefobj)