code: def get_word_index(
      dest_dir="/tmp/.bigdl/dataset", filename="imdb_word_index.pkl"
  ):
      """Retrieves the dictionary mapping word indices back to words.
  
      # Arguments
          dest_dir: where to cache the data (relative to `~/.bigdl/dataset`).
          filename: dataset file name
  
      # Returns
          The word index dictionary.
      """
  
      path = base.maybe_download(
          filename,
          dest_dir,
          "https://s3.amazonaws.com/text-datasets/imdb_word_index.pkl",
      )
      with open(path, "rb") as f:
          data = cPickle.load(f, encoding="latin1")
  
      return data
  
imports: from bigdl.dllib.feature.dataset import base
  import numpy
  from six.moves import cPickle
label_desc: Use image node_id 4 for calling a global function with example usage: get_word_index(dest_dir, filename) and returns: data