code: def test_export_model(tuner_fn, tmp_path):
      tuner_class = tuner_fn.return_value
      tuner = tuner_class.return_value
  
      x_train = np.random.rand(100, 32, 32, 3)
      y_train = np.random.rand(100, 1)
  
      auto_model = get_single_io_auto_model(tmp_path)
      auto_model.fit(
          x_train, y_train, epochs=2, validation_data=(x_train, y_train)
      )
      auto_model.export_model()
      assert tuner.get_best_model.called
  
imports: from unittest import mock
  import keras_tuner
  import numpy
  import pytest
  import tensorflow
  import autokeras
  from autokeras import test_utils
label_desc: Use image node_id 12 for calling a global function with example usage: test_export_model(tuner_fn, tmp_path) without return types