def test_make_empty(self):
        npboxes = np.empty((0, 4))
        class_ids = np.empty((0, ))
        scores = np.empty((0, ))
        expected_labels = ObjectDetectionLabels(
            npboxes, class_ids, scores=scores)

        labels = ObjectDetectionLabels.make_empty()
        labels.assert_equal(expected_labels)
    def test_filter_by_aoi(self):
        aois = [Box.make_square(0, 0, 2).to_shapely()]
        filt_labels = self.labels.filter_by_aoi(aois)

        npboxes = np.array([[0., 0., 2., 2.]])
        class_ids = np.array([1])
        scores = np.array([0.9])
        exp_labels = ObjectDetectionLabels(npboxes, class_ids, scores=scores)
        self.assertEqual(filt_labels, exp_labels)

        aois = [Box.make_square(4, 4, 2).to_shapely()]
        filt_labels = self.labels.filter_by_aoi(aois)
        exp_labels = ObjectDetectionLabels.make_empty()
        self.assertEqual(filt_labels, exp_labels)