code: def test_gpu_save_load_export(self):
      old_num_gpus = tc.config.get_num_gpus()
      gpu_options = set([old_num_gpus, 0, 1])
      for in_gpus in gpu_options:
          for out_gpus in gpu_options:
              tc.config.set_num_gpus(in_gpus)
              model = tc.image_similarity.create(
                  self.sf,
                  feature=self.feature,
                  label=None,
                  model=self.pre_trained_model,
              )
              with TempDirectory() as filename:
                  model.save(filename)
                  tc.config.set_num_gpus(out_gpus)
                  model = tc.load_model(filename)
  
      tc.config.set_num_gpus(old_num_gpus)
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import pytest
  import turicreate
  from turicreate.toolkits._internal_utils import _mac_ver
  import tempfile
  import shutil
  import coremltools
  import numpy
  from turicreate.toolkits._main import ToolkitError
label_desc: Use image node_id 2 for calling the ImageSimilarityGPUTest obj's underlying member method code with example usage: obj.test_gpu_save_load_export() without return types