code: def setUp(self):
      self.phi1 = ContinuousFactor(["x", "y"], self.pdf1)
      self.phi2 = ContinuousFactor(["x1", "x2"], self.pdf2)
      self.phi3 = ContinuousFactor(["x", "y", "z"], self.pdf3)
      self.phi4 = ContinuousFactor(["x1", "x2", "x3"], self.pdf4)
  
imports: import unittest
  import numpy
  import numpy.testing
  from scipy.special import beta
  from scipy.stats import multivariate_normal
  from pgmpy.factors.continuous import ContinuousFactor
label_desc: Use image node_id 5 for calling the TestContinuousFactorMethods obj's underlying member method code with example usage: obj.setUp() without return types