code: def setUp(self):
      self.phi1 = GD(
          ["x1", "x2", "x3"],
          np.array([[1], [-3], [4]]),
          np.array([[4, 2, -2], [2, 5, -5], [-2, -5, 8]]),
      )
      self.phi2 = GD(["x"], [0], [[1]])
      self.phi3 = self.phi1.copy()
  
imports: import unittest
  import numpy
  import numpy.testing
  from pgmpy.factors.distributions import GaussianDistribution
label_desc: Use image node_id 1 for calling the TestJGDMethods obj's underlying member method code with example usage: obj.setUp() without return types