code: def test_serialize(
      Estimator, serialize_test, hyperparameters, is_iqf
  ):
      hyperparameters.update(is_iqf=is_iqf)
      serialize_test(Estimator, hyperparameters)
  
file_path: gluonts/test/mx/model/seq2seq/test_model.py
imports: import pytest
  from gluonts.mx import MQCNNEstimator, MQRNNEstimator
  from gluonts.mx.distribution import GaussianOutput, ISQFOutput
  from gluonts.testutil.dummy_datasets import make_dummy_datasets_with_features
label_desc: Use image node_id 9 for calling a global function with example usage: test_serialize(Estimator, serialize_test, hyperparameters, is_iqf) without return types