code: def _get_jpeg(height, width):
      """Returns jpeg picture."""
      image = fake_data_utils.get_random_picture(height, width)
      jpeg = tf.image.encode_jpeg(image)
      with utils.nogpu_session() as sess:
          res = sess.run(jpeg)
      return res
  
file_path: datasets/tensorflow_datasets/testing/fake_data_generation/caltech.py
imports: import os
  from absl import app
  from absl import flags
  import numpy
  from tensorflow_datasets.core import utils
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  from tensorflow_datasets.image_classification import caltech
  import tensorflow_datasets.public_api
  from tensorflow_datasets.testing import fake_data_utils
label_desc: Use image node_id 3 for calling a global function with example usage: _get_jpeg(height, width) and returns: res