code: def url_to_filename(url, etag=None):
      """
      Convert `url` into a hashed filename in a repeatable way.
      If `etag` is specified, append its hash to the url's, delimited
      by a period.
      """
      url_bytes = url.encode("utf-8")
      url_hash = sha256(url_bytes)
      filename = url_hash.hexdigest()
  
      if etag:
          etag_bytes = etag.encode("utf-8")
          etag_hash = sha256(etag_bytes)
          filename += "." + etag_hash.hexdigest()
  
      return filename
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import json
  import logging
  import os
  import shutil
  import tempfile
  from functools import wraps
  from hashlib import sha256
  import sys
  from io import open
  import boto3
  import requests
  from botocore.exceptions import ClientError
  from tqdm import tqdm
label_desc: Use image node_id 1 for calling a global function with example usage: url_to_filename(url, etag) and returns: filename