code: def setup_class(cls):
      cls.chem = np.array(
          [
              2.20,
              2.20,
              2.4,
              2.4,
              2.5,
              2.7,
              2.8,
              2.9,
              3.03,
              3.03,
              3.10,
              3.37,
              3.4,
              3.4,
              3.4,
              3.5,
              3.6,
              3.7,
              3.7,
              3.7,
              3.7,
              3.77,
              5.28,
              28.95,
          ]
      )
  
imports: import numpy
  from numpy.random import standard_normal
  from numpy.testing import assert_almost_equal, assert_equal
  import pytest
  from scipy.stats import norm
  import statsmodels.api
  import statsmodels.robust.scale
  from statsmodels.robust.scale import mad
label_desc: Use image node_id 1 for calling the TestChem obj's underlying member method code with example usage: obj.setup_class(cls) without return types