Testing access to derived channels for .accs_derived

tests/test_roiset.py

@@ -224,6 +224,10 @@ class TestRoiSetMonoProducts(BaseTestRoiSetMonoProducts, unittest.TestCase):
         )
         self.assertTrue(all(roiset.get_df()['classify_by_multiple_input_model'].unique() == [3]))
         self.assertTrue(all(np.unique(roiset.object_class_maps['multiple_input_model'].data) == [0, 3]))
+
+        self.assertEqual(len(roiset.accs_derived), 2)
+        for di in roiset.accs_derived:
+            self.assertEqual(roiset.get_patches_acc().shape, di.shape)
         return roiset
 
     def test_export_object_classes(self):