'Persist this model into the passed directory. Returns the metadata necessary to load the model again.'

def persist(self, model_dir):

    import cloudpickle
    classifier_file = os.path.join(model_dir, u'intent_classifier.pkl')
    with io.open(classifier_file, u'wb') as f:
        cloudpickle.dump(self, f)
    return {u'intent_classifier_sklearn': u'intent_classifier.pkl'}
