code: def test_pickle(normal_posterior):
      fit1 = normal_posterior.sample(stepsize=0.001)
      assert fit1["y"] is not None
      with tempfile.TemporaryFile() as fp:
          pickle.dump(fit1, fp)
          fp.seek(0)
          fit2 = pickle.load(fp)
      assert fit2["y"] is not None
      np.testing.assert_array_equal(fit1["y"], fit2["y"])
  
imports: import pickle
  import tempfile
  import numpy
  import pytest
  import stan
label_desc: Use image node_id 2 for calling a global function with example usage: test_pickle(normal_posterior) without return types