code: def test_invalid_fit(self, data):
      if pystan_version() == 2:
          model = data.model
          model_data = {
              "J": 8,
              "y": np.array(
                  [28.0, 8.0, -3.0, 7.0, -1.0, 1.0, 18.0, 12.0]
              ),
              "sigma": np.array(
                  [15.0, 10.0, 16.0, 11.0, 9.0, 11.0, 10.0, 18.0]
              ),
          }
          fit_test_grad = model.sampling(
              data=model_data,
              test_grad=True,
              check_hmc_diagnostics=False,
          )
          with pytest.raises(AttributeError):
              _ = from_pystan(posterior=fit_test_grad)
          fit = model.sampling(
              data=model_data,
              iter=100,
              chains=1,
              check_hmc_diagnostics=False,
          )
          del fit.sim["samples"]
          with pytest.raises(AttributeError):
              _ = from_pystan(posterior=fit)
  
imports: import importlib
  from collections import OrderedDict
  import numpy
  import pytest
  from ...None import from_pystan
  from ...data.io_pystan import get_draws, get_draws_stan3
  from ..helpers import chains, check_multiple_attrs, draws, eight_schools_params, importorskip, load_cached_models, pystan_version, running_on_ci
label_desc: Use image node_id 9 for calling the TestDataPyStan obj's underlying member method code with example usage: obj.test_invalid_fit(data) without return types