code: def split(sentence):
      return (
          sentence.lower().replace(".", " .").replace(",", " ,").split()
      )
  
file_path: chainer/examples/image_captioning/datasets.py
imports: from collections import defaultdict
  import os
  import numpy
  from PIL import Image
  from pycocotools.coco import COCO
  from chainer import dataset
  from chainer.dataset.convert import to_device
label_desc: Use image node_id 1 for calling a global function with example usage: split(sentence) and returns: sentence