code: def test_quantize_tf(self):
      for model, model_kwargs in OnnxExportTestCase.MODEL_TO_TEST:
          path = self._test_export(model, "tf", 12, **model_kwargs)
          quantized_path = quantize(Path(path))
  
          # Ensure the actual quantized model is not bigger than the original one
          if quantized_path.stat().st_size >= Path(path).stat().st_size:
              self.fail(
                  "Quantized model is bigger than initial ONNX model"
              )
  
imports: import unittest
  from pathlib import Path
  from tempfile import NamedTemporaryFile, TemporaryDirectory
  from transformers import BertConfig, BertTokenizerFast, FeatureExtractionPipeline
  from transformers.convert_graph_to_onnx import convert, ensure_valid_input, generate_identified_filename, infer_shapes, quantize
  from transformers.testing_utils import require_tf, require_tokenizers, require_torch, slow
label_desc: Use image node_id 4 for calling the OnnxExportTestCase obj's underlying member method code with example usage: obj.test_quantize_tf() without return types