code: def test_params(self):
      # note: only testing slope coefficients
      # constant is far off in example 4 versus 2
      assert_almost_equal(
          self.res1.params[1:], self.res2.params[1:], decimal=2
      )
      # constant
      assert_almost_equal(
          self.res1.params[1], self.res2.params[1], decimal=2
      )
  
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 3 for calling the CheckAM obj's underlying member method code with example usage: obj.test_params() without return types