code: def setUp(self):
      mean = np.array([1, 2, 3, 4])
      covariance = np.array(
          [
              [1, 0.2, 0.4, 0.7],
              [0.2, 2, 0.5, 0.8],
              [0.4, 0.5, 3, 0.6],
              [0.7, 0.8, 0.6, 4],
          ]
      )
      self.test_model = JGD(["x", "y", "z", "t"], mean, covariance)
      self.test_gradient = GradLogPDFGaussian(
          [0, 0, 0, 0], self.test_model
      )
  
imports: import unittest
  import numpy
  from pgmpy.factors.distributions import GaussianDistribution
  from pgmpy.sampling import LeapFrog, ModifiedEuler, GradLogPDFGaussian
label_desc: Use image node_id 1 for calling the TestGradLogPDFGaussian obj's underlying member method code with example usage: obj.setUp() without return types