code: def _get_hparams_path():
    
    hparams_path = None
    if FLAGS.output_dir:
      hparams_path = os.path.join(FLAGS.output_dir, "hparams.json")
    else:
      tf.logging.warning(
          "--output_dir not specified. Hyper-parameters will be infered from"
          "--hparams_set and --hparams only. These may not match training time"
          "hyper-parameters.")
    return hparams_path
docs: Get hyper-parameters file path.