code: def test_valid_tags(self):
      valid_tags = dataset_metadata.valid_tags()
      self.assertIn("content.data-type.image", valid_tags)
  
imports: from tensorflow_datasets import testing
  from tensorflow_datasets.core import dataset_metadata
  from tensorflow_datasets.core.utils import resource_utils
label_desc: Use image node_id 2 for calling the DatasetMetadataTest obj's underlying member method code with example usage: obj.test_valid_tags() without return types