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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_permissions_for_registration(self):
 """ Utilised by Wagtail's 'register_permissions' hook to allow permissions for a all models grouped by this class to be assigned to Groups in settings. """

        qs = Permission.objects.none()
        for instance in self.modeladmin_instances:
            qs = qs | instance.get_permissions_for_registration()
        return qs