class _SignallingSession(Session):

    def __init__(self, db, autocommit=False, autoflush=False, **options):
        import pdb; pdb.set_trace() # <-- this is temporary!
        self.app = db.get_app()
        self._model_changes = {}
        Session.__init__(self, autocommit=autocommit, autoflush=autoflush,
                         extension=db.session_extensions,
                         bind=db.engine,
                         binds=db.get_binds(self.app), **options)
