code: def setup_class(cls):
      super().setup_class()  # initialize DGP
  
      cls.family = family.Gamma(links.Log())
      cls.rvs = stats.gamma.rvs
  
      cls.init()
  
imports: from statsmodels.compat.python import lrange
  import numpy
  from numpy.testing import assert_almost_equal, assert_equal
  from scipy import stats
  import pytest
  from statsmodels.sandbox.gam import AdditiveModel
  from statsmodels.sandbox.gam import Model
  from statsmodels.genmod.families import family, links
  from statsmodels.genmod.generalized_linear_model import GLM
  from statsmodels.regression.linear_model import OLS
label_desc: Use image node_id 1 for calling the TestGAMGamma obj's underlying member method code with example usage: obj.setup_class(cls) without return types