code: def make_tokens_list(dir_, filters):
      
      with open(tokens_dir + dir_ + '/sources.json', 'r') as injson:
          data = json.load(injson)
          sources = [corpora_dir + fname for fname in data]
  
      with open('data/skipwords.txt', 'r') as f:
          skipwords = [line.rstrip() for line in f]
  
      tokens_list = []
      for fname in sources:
          print("Incorporating tokens from " + fname)
          with open(fname, 'r') as injson:
              data = json.load(injson)
              words = [w.lower() for w in data if not w == '']
              filtered = [w for w,p in nltk.pos_tag(words) if p in filters]
              sanitized = [w for w in filtered if not w in skipwords]
              tokens_list += sanitized
  
      tokens_list = list(set(tokens_list)) # unique
      target = tokens_dir + dir_ + '/' + '-'.join(filters) + '.json'
      with open(target, 'w') as outjson:
          json.dump(tokens_list, outjson)
docs: Find sources.json in <dir_>. It contains a list of tokenized texts. For
      each tokenized text listed in sources.json, read its tokens, filter them,
      and add them to an aggregated list. Write the aggregated list to disk using
      a filename based on the <filters> given.