code: def test_call_none_example_feature_columns(self):
      with self.assertRaisesRegexp(
          ValueError,
          r"example_feature_columns or "
          "example_hidden_layer_dims must not be empty.",
      ):
          gam.GAMRankingNetwork(
              context_feature_columns=self.context_feature_columns,
              example_feature_columns=None,
              example_hidden_layer_dims=["10", "10"],
              context_hidden_layer_dims=["10", "10"],
              activation=tf.nn.relu,
              dropout=0.5,
              name="gam_ranking_model",
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import tensorflow.compat.v2
  from tensorflow_ranking.python.keras import losses
  from tensorflow_ranking.python.keras import metrics
  from tensorflow_ranking.python.keras import model
  from tensorflow_ranking.python.keras.canned import gam
label_desc: Use image node_id 7 for calling the GAMRankingNetworkTest obj's underlying member method code with example usage: obj.test_call_none_example_feature_columns() without return types