'Passing preprocessors to the learner constructor should override the
default preprocessors defined on the learner'

def test_overrides_custom_preprocessors(self):

    pp = Discretize()
    learner = DummyLearnerPP(preprocessors=(pp,))
    self.assertEqual(tuple(learner.active_preprocessors), (pp,), 'Learner    should    override    default    preprocessors    when    specified    in    constructor')
