code: def test_error(self):
      with self.assertRaises(TypeError):
          _ = MXDataGenerator("data_loader", size=10, batch_size=5)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import unittest
  import tensorflow
  import numpy
  from keras.preprocessing.image import ImageDataGenerator
  from art.data_generators import KerasDataGenerator, PyTorchDataGenerator, MXDataGenerator, TensorFlowDataGenerator
  from art.data_generators import TensorFlowV2DataGenerator, NumpyDataGenerator
  from tests.utils import master_seed
label_desc: Use image node_id 4 for calling the TestMXGenerator obj's underlying member method code with example usage: obj.test_error() without return types