code: def make_example_from_ref(url, ref):
      try:
          url = encode(url)
          ref = encode(ref)
      except UnicodeEncodeError:
          return None
  
      features = {
          "url": tf.train.Feature(
              bytes_list=tf.train.BytesList(value=[url])
          ),
          "content": tf.train.Feature(
              bytes_list=tf.train.BytesList(value=[ref])
          ),
      }
      return tf.train.Example(
          features=tf.train.Features(feature=features)
      )
  
imports: import datetime
  import json
  import math
  import multiprocessing
  import os
  import random
  import asyncio
  import aiohttp
  import tensorflow
  from tensor2tensor.data_generators.wikisum import html
  from tensor2tensor.data_generators.wikisum import utils
label_desc: Use image node_id 5 for calling a global function with example usage: make_example_from_ref(url, ref) and returns: tf, None