text: 
  from nose.tools import eq_
  
  from libctw import ctw
  
  def test_impossible_history():
      model = ctw.create_model(deterministic=True, max_depth=2)
      model.see_generated([0, 0, 0])
      eq_(0.0, model.predict_one())
  
      model.revert_generated(3)
      eq_(0.5, model.predict_one())
      model.see_generated([1, 1, 1])
      eq_(1.0, model.predict_one())
  
  def test_sure():
      model = ctw.create_model(deterministic=True, max_depth=2)
      model.see_generated([1, 1, 1])
      eq_(1.0, model.predict_one())
  
  