def test_type(self):
        rset = event.ResultSet()
        with pytest.raises(NotImplementedError):
            rset.extend([])
        with pytest.raises(NotImplementedError):
            rset.extend(False)
def _init_signals(self):
        """Initializes the backends and gtk signals """
        self.connect("cursor-changed", self.on_select_row)
        _signals = BackendSignals()
        _signals.connect(_signals.BACKEND_ADDED, self.on_backend_added)
        _signals.connect(_signals.BACKEND_STATE_TOGGLED,
                         self.on_backend_state_changed)