code: def test_class_init(self):
      mu = np.array([7, 13])
      sigma = np.array([[4, 3], [3, 6]])
  
      cpd1 = LinearGaussianCPD(
          "Y",
          evidence_mean=mu,
          evidence_variance=sigma,
          evidence=["X1", "X2"],
      )
      self.assertEqual(cpd1.variable, "Y")
      self.assertEqual(cpd1.evidence, ["X1", "X2"])
  
file_path: pgmpy/pgmpy/tests/test_factors/test_continuous/test_Linear_Gaussian_CPD.py
imports: import unittest
  import numpy.testing
  import pandas
  import numpy
  from pgmpy.factors.continuous import LinearGaussianCPD
label_desc: Use image node_id 1 for calling the TestLGCPD obj's underlying member method code with example usage: obj.test_class_init() without return types