class_docstr: A single training instance (sentence pair).
class_docstr_tok: ["A","single","training","instance","(","sentence","pair",")","."]
code: def __init__(
      self,
      tokens,
      segment_ids,
      masked_lm_positions,
      masked_lm_labels,
      is_random_next,
      vocab,
  ):
      self.tokens = tokens
      self.segment_ids = segment_ids
      self.is_random_next = is_random_next
      self.masked_lm_positions = masked_lm_positions
      self.masked_lm_labels = masked_lm_labels
      self.vocab = vocab
  
imports: import argparse
  import logging
  import io
  import os
  import glob
  import collections
  import warnings
  import random
  import time
  from multiprocessing import Pool
  import numpy
  from gluonnlp.models.bert import BertModel, BertForPretrain, get_pretrained_bert
  import gluonnlp
label_desc: Use image node_id 1 to create a new TrainingInstance object  with example: obj = TrainingInstance(tokens, segment_ids, masked_lm_positions, masked_lm_labels, is_random_next, vocab)