docstr: Tests training and evaluation loop using mocked data.
docstr_tok: ["Tests","training","and","evaluation","loop","using","mocked","data","."]
code: def test_train_and_evaluate(self, model):
      """Tests training and evaluation loop using mocked data."""
      # Create a temporary directory where tensorboard metrics are written.
      workdir = tempfile.mkdtemp()
  
      # Go two directories up to the root of the flax directory.
      flax_root_dir = pathlib.Path(__file__).parents[2]
      data_dir = str(flax_root_dir) + "/.tfds/metadata"
  
      # Define training configuration
      config = default_lib.get_config()
      config.model = model
      config.batch_size = 1
      config.num_epochs = 1
      config.num_train_steps = 1
      config.steps_per_eval = 1
  
      with tfds.testing.mock_data(num_examples=1, data_dir=data_dir):
          train.train_and_evaluate(workdir=workdir, config=config)
  
file_path: flax/examples/imagenet/train_test.py
imports: import pathlib
  import tempfile
  from absl.testing import absltest
  from absl.testing import parameterized
  import jax
  from jax import random
  import tensorflow
  import tensorflow_datasets
  import models
  import train
  from configs import default
label_desc: Use image node_id 4 for calling the TrainTest obj's underlying member method code with example usage: obj.test_train_and_evaluate(model) without return types