code: def convert_strings_to_uint8_arrays(str_tensor, max_str_len=None):
      """Convert string numpy array into uint8 arrays to transfer to TPUs.
  
      Given the input string array, outputs a uint8 tensor with an additional
      dimension at the end with the size of max_str_len.
  
      Args:
        str_tensor: The input string array.
        max_str_len: The maximum number of characters to keep in the converted uint8
          array. If None, it is set to the longest string length in the input array.
  
      Returns:
        Converted uint8 numpy array with an additional dim of size max_str_len.
      """
      # Make sure that the input str_tensor is an np.ndarray of bytes not of object.
      # An object array stores pointers only whereas a bytes array stores actual
      # string bytes
      str_tensor = np.array(str_tensor, dtype=bytes)
      uint8_tensor = np.frombuffer(str_tensor, np.uint8).reshape(
          str_tensor.shape + (-1,)
      )
      if max_str_len:
          to_pad = max(0, max_str_len - uint8_tensor.shape[-1])
          uint8_tensor = np.pad(
              uint8_tensor[..., :max_str_len],
              [[0, 0]] * str_tensor.ndim + [[0, to_pad]],
          )
  
      return uint8_tensor
  
imports: import os
  import re
  from typing import Any, Callable, Dict, List, Mapping, Optional, Tuple, Union
  from absl import logging
  import flax
  from flax import struct
  from flax.core import frozen_dict
  import flax.linen
  from flax.training import checkpoints
  import jax
  import jax.numpy
  import jax.profiler
  import ml_collections
  import numpy
  import optax
  from scenic.dataset_lib import dataset_utils
  from scenic.model_lib.base_models import base_model
  from scenic.projects.baselines.clip import model
  from scenic.train_lib import lr_schedules
  from scenic.train_lib import optimizers
  from scenic.train_lib import train_utils
  from tensorflow.io import gfile
label_desc: Use image node_id 12 for calling a global function with example usage: convert_strings_to_uint8_arrays(str_tensor, max_str_len) and returns: uint8_tensor