code: def prepare_data(args, config, train_path):
      """Downloads the PTB or COCO dataset"""
      if not os.path.exists(config.log_dir):
          os.mkdir(config.log_dir)
  
      ptb_url = "https://jxhe.github.io/download/ptb_data.tgz"
      coco_url = "https://VegB.github.io/downloads/coco_data.tgz"
  
      data_path = args.data_path
  
      if not tf.gfile.Exists(train_path):
          url = ptb_url if args.dataset == "ptb" else coco_url
          tx.data.maybe_download(url, data_path, extract=True)
          os.remove("%s_data.tgz" % args.dataset)
  
imports: import os
  import argparse
  import importlib
  import tensorflow
  import texar.tf
label_desc: Use image node_id 1 for calling a global function with example usage: prepare_data(args, config, train_path) without return types