code: def init(cls):
      cls.res2 = cls.mod2.fit()
      mod = GLM(cls.endog, cls.exog)
      mod.exog_names[:] = ["const", "x1", "x2", "x3", "x4"]
      cls.res1 = mod.fit_constrained("x1=0.5")
  
imports: import warnings
  import numpy
  from numpy.testing import assert_allclose, assert_equal
  from statsmodels.genmod.families import family
  from statsmodels.genmod.generalized_linear_model import GLM
  from statsmodels.regression.linear_model import OLS, WLS
  from statsmodels.tools.sm_exceptions import ValueWarning
  from statsmodels.tools.tools import add_constant
label_desc: Use image node_id 1 for calling the TestGLMGaussianConstrained obj's underlying member method code with example usage: obj.init(cls) without return types