new_contents: from pybbn.graph.dag import BbnUtil
  from pybbn.pptc.potentialinitializer import PotentialInitializer
  from pybbn.pptc.moralizer import Moralizer
  from pybbn.pptc.triangulator import Triangulator
  from pybbn.pptc.transformer import Transformer
  from pybbn.pptc.initializer import Initializer
  from pybbn.pptc.propagator import Propagator
  from nose import with_setup
  
  
  def setup():
      pass
  
  
  def teardown():
      pass
  
  
  @with_setup(setup, teardown)
  def test_propagator():
      bbn = BbnUtil.get_huang_graph()
      PotentialInitializer.init(bbn)
  
      ug = Moralizer.moralize(bbn)
      cliques = Triangulator.triangulate(ug)
  
      join_tree = Transformer.transform(cliques)
  
      Initializer.initialize(join_tree)
      Propagator.propagate(join_tree)
  
      # assert later
      # for clique in join_tree.get_cliques():
      #     potential = join_tree.potentials[clique.id]
      #     print(clique)
      #     print(potential)
      #     total = sum([entry.value for entry in potential.entries])
      #     print('total {}'.format(total))
      # assert 1 == 2
  
subject: add propagator test