docstr: Test saving model with unsupported extension.
docstr_tok: ["Test","saving","model","with","unsupported","extension","."]
code: def test_save_unsupported_extension(self):
      """Test saving model with unsupported extension."""
      model = self.get_model()
      with self.assertRaisesRegex(
          ValueError, "Invalid filepath extension for saving"
      ):
          saving_api.save_model(model, "model.png")
  
imports: import os
  import unittest.mock
  import numpy
  from absl import logging
  from keras import layers
  from keras.models import Sequential
  from keras.saving import saving_api
  from keras.testing import test_case
label_desc: Use image node_id 6 for calling the SaveModelTests obj's underlying member method code with example usage: obj.test_save_unsupported_extension() without return types