code: def test_to_blob(self, example):
      blob = content_types.to_blob(example)
      self.assertIsInstance(blob, glm.Blob)
      self.assertEqual(blob.mime_type, "image/png")
      self.assertStartsWith(blob.data, b"\x89PNG")
  
imports: import copy
  import pathlib
  import unittest.mock
  from absl.testing import absltest
  from absl.testing import parameterized
  import google.ai.generativelanguage
  import google.generativeai
  from google.generativeai.types import content_types
  from google.generativeai.types import safety_types
  import IPython.display
  import PIL.Image
label_desc: Use image node_id 3 for calling the UnitTests obj's underlying member method code with example usage: obj.test_to_blob(example) without return types