code: def test_mocking_add_tfds_id():
      read_config = tfds.ReadConfig(add_tfds_id=True)
      ds = tfds.load("mnist", split="train", read_config=read_config)
      assert ds.element_spec == {
          "tfds_id": tf.TensorSpec(shape=(), dtype=tf.string),
          "image": tf.TensorSpec(shape=(28, 28, 1), dtype=tf.uint8),
          "label": tf.TensorSpec(shape=(), dtype=tf.int64),
      }
      train_examples = list(ds.take(3))  # Iteration should work
      ds = tfds.load("mnist", split="test", read_config=read_config)
      test_examples = list(ds.take(3))  # Iteration should work
      assert train_examples[0]["tfds_id"] != test_examples[0]["tfds_id"]
  
imports: import functools
  import pickle
  import numpy
  import pytest
  import tensorflow
  import tensorflow_datasets
label_desc: Use image node_id 4 for calling a global function with example usage: test_mocking_add_tfds_id() without return types