code: def test_serialization():
      layer = PolynomialCrossing(projection_dim=None)
      serialized_layer = tf.keras.layers.serialize(layer)
      new_layer = tf.keras.layers.deserialize(serialized_layer)
      assert layer.get_config() == new_layer.get_config()
  
file_path: addons/tensorflow_addons/layers/tests/polynomial_test.py
imports: import pytest
  import numpy
  import tensorflow
  from tensorflow_addons.layers.polynomial import PolynomialCrossing
label_desc: Use image node_id 5 for calling a global function with example usage: test_serialization() without return types