fix for spectrum dataset
@@ -552,7 +552,7 @@ def test_map_dataset_onoff_fits_io(images, tmp_path):
dataset.write(tmp_path / "test.fits")
dataset_new = MapDatasetOnOff.read(tmp_path / "test.fits")
- assert len(dataset_new.model) == 0
+ assert dataset_new.model is None
assert dataset_new.mask.dtype == bool
assert_allclose(dataset.counts.data, dataset_new.counts.data)
