code: def slice(dataset, batch_size=10):
      grouper = SentenceGrouper([5, 10, 20, 50])
      return grouper.slice(dataset, batch_size)
  
imports: import math
  import random
  import sys
  import numpy
  import tensorflow
  from .sentence_grouper import SentenceGrouper
  from ..tf2contrib import *
label_desc: Use image node_id 19 for calling the NerModel obj's underlying member method code with example usage: obj.slice(dataset, batch_size) and returns: grouper