def METHOD_NAME(self, sample_dataset, data_var, expected_keys):
    idx = "time"
    da = sample_dataset.data_vars[data_var]
    serial = NCFile.da_to_dict(da, index_dim=idx)
    assert all(map(lambda x: x in serial.keys(), expected_keys))
    delayed = NCFile.da_to_dict_delayed(da, index_dim=idx)
    assert all(
        map(lambda key: np.allclose(serial[key], delayed[key]),
            expected_keys
        )
    )