code: def test_add_multiple_factors(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)
      self.assertCountEqual(self.graph.factors, [phi1, phi2])
  
imports: import unittest
  import numpy
  from pgmpy.factors.discrete import DiscreteFactor
  from pgmpy.models import ClusterGraph
  from pgmpy.tests import help_functions
label_desc: Use image node_id 4 for calling the TestClusterGraphFactorOperations obj's underlying member method code with example usage: obj.test_add_multiple_factors() without return types