code: def tok_file_name(filename, lang):
      seps = filename.split(".")
      seps.insert(-1, "tok")
      tok_file = ".".join(seps)
      return tok_file
  
imports: import itertools
  import os
  import csv
  from collections import defaultdict
  from six.moves import zip
  import io
  import wget
  import sys
  from subprocess import check_call, check_output
label_desc: Use image node_id 4 for calling a global function with example usage: tok_file_name(filename, lang) and returns: tok_file