def apply_many(self, features):
    if (len(features) == 0):
        return features
    for m in self.models:
        features = m.apply_many(features)
    return features
def apply_many(self, features):
    if (len(features) == 0):
        return features
    for m in self.models:
        features = m.apply_many(features)
    return features