code: def test_copy_with_factorchanges(self):
      self.graph.add_edges_from([[("a", "b"), ("b", "c")]])
      phi1 = DiscreteFactor(["a", "b"], [2, 2], np.random.rand(4))
      phi2 = DiscreteFactor(["b", "c"], [2, 2], np.random.rand(4))
      self.graph.add_factors(phi1, phi2)
      graph_copy = self.graph.copy()
  
      self.graph.factors[0].reduce([("a", 0)])
      self.assertNotEqual(
          self.graph.factors[0].scope(), graph_copy.factors[0].scope()
      )
      self.assertNotEqual(self.graph, graph_copy)
      self.graph.factors[1].marginalize(["b"])
      self.assertNotEqual(
          self.graph.factors[1].scope(), graph_copy.factors[1].scope()
      )
      self.assertNotEqual(self.graph, graph_copy)
  
imports: import unittest
  import numpy
  from pgmpy.factors.discrete import DiscreteFactor
  from pgmpy.models import JunctionTree
  from pgmpy.tests import help_functions
label_desc: Use image node_id 4 for calling the TestJunctionTreeCopy obj's underlying member method code with example usage: obj.test_copy_with_factorchanges() without return types