code: def bert_tokenizer(vocab_path=None):
      """Constructs a BERT tokenizer."""
      # This import is from https://github.com/google-research/bert which is not
      # listed as a dependency in trax.
      # TODO(piotrekp1): using SubwordTextEncoder instead after fixing the
      # differences
      from bert.tokenization.bert_tokenization import (
          FullTokenizer,
      )  # pylint: disable=g-import-not-at-top
  
      if vocab_path is None:
          raise ValueError(
              "vocab_path is required to construct the BERT tokenizer."
          )
      tokenizer = FullTokenizer(vocab_path, do_lower_case=True)
      return tokenizer
  
file_path: trax/trax/supervised/pretrain_finetune.py
imports: import functools
  import gin
  import numpy
  import tensorflow_datasets
  from trax.data.inputs import Inputs
label_desc: Use image node_id 3 for calling a global function with example usage: bert_tokenizer(vocab_path) and returns: tokenizer