code: def test_bad_unpickle():
      with pm.Model() as model:
          pm.Normal("x")
  
      with model:
          step = pm.NUTS()
          step.no_unpickle = NoUnpickle()
          with pytest.raises(Exception) as exc_info:
              pm.sample(
                  tune=2,
                  draws=2,
                  mp_ctx="spawn",
                  step=step,
                  cores=2,
                  chains=2,
                  compute_convergence_checks=False,
              )
          assert "could not be unpickled" in str(
              exc_info.getrepr(style="short")
          )
  
imports: import multiprocessing
  import os
  import platform
  import sys
  import warnings
  import cloudpickle
  import numpy
  import pytensor
  import pytensor.tensor
  import pytest
  from pytensor.compile.ops import as_op
  from pytensor.tensor.type import TensorType
  import pymc
  import pymc.sampling.parallel
  from pymc.pytensorf import floatX
label_desc: Use image node_id 2 for calling a global function with example usage: test_bad_unpickle() without return types