code: def unzip_data(download_dir, data_gz):
      data_dir = download_dir + "aclImdb"
      if not os.path.exists(data_dir):
          print("extracting %s to %s" % (download_dir, data_dir))
          with tarfile.open(data_gz) as tar:
              tar.extractall(download_dir)
      return data_dir
  
imports: import re
  import os
  import pickle
  import urllib
  import tarfile
  import numpy
  import pandas
  import nltk
  from nltk.stem import PorterStemmer
  from nltk.tokenize.toktok import ToktokTokenizer
  from gensim.models.keyedvectors import KeyedVectors
  from sklearn.model_selection import train_test_split
  from bs4 import BeautifulSoup
label_desc: Use image node_id 4 for calling a global function with example usage: unzip_data(download_dir, data_gz) and returns: data_dir