code: def test_unknown_method(self):
      with self.assertRaises(ValueError):
          self.extractor.extract("from/path", NO_EXTRACT, "to/path")
  
imports: import os
  from unittest import mock
  import tensorflow
  from tensorflow_datasets import testing
  from tensorflow_datasets.core.download import extractor
  from tensorflow_datasets.core.download import resource
label_desc: Use image node_id 3 for calling the ExtractorTest obj's underlying member method code with example usage: obj.test_unknown_method() without return types