code: def test_export_format(self):
      toolkit = core.ModelCardToolkit(output_dir=self.mct_dir)
      mc = toolkit.scaffold_assets()
      mc.model_details.name = "My Model"
      toolkit.update_model_card(mc)
      result = toolkit.export_format()
  
      proto_path = os.path.join(self.mct_dir, "data/model_card.proto")
      self.assertTrue(os.path.exists(proto_path))
      model_card_proto = io_utils.parse_proto_file(
          proto_path, model_card_pb2.ModelCard()
      )
      self.assertEqual(model_card_proto.model_details.name, "My Model")
  
      model_card_path = os.path.join(
          self.mct_dir, "model_cards/model_card.html"
      )
      self.assertTrue(os.path.exists(model_card_path))
      content = io_utils.read_file(model_card_path)
      self.assertEqual(content, result)
      self.assertTrue(content.startswith("<!DOCTYPE html>"))
      self.assertIn("My Model", content)
  
file_path: model-card-toolkit/model_card_toolkit/core_test.py
imports: import os
  from absl import flags
  from absl.testing import absltest
  from model_card_toolkit import core
  from model_card_toolkit.proto import model_card_pb2
  from model_card_toolkit.utils import io_utils
label_desc: Use image node_id 6 for calling the CoreTest obj's underlying member method code with example usage: obj.test_export_format() without return types