code: def _worker_prefix(output_prefix: str, worker_id: int):
      return f"{output_prefix}.pt{worker_id}"
  
imports: import logging
  import os
  import typing
  from abc import ABC, abstractmethod
  from collections import Counter
  from dataclasses import dataclass
  from multiprocessing import Pool
  import torch
  from fairseq.data import Dictionary, indexed_dataset
  from fairseq.file_chunker_utils import Chunker, find_offsets
  from fairseq.file_io import PathManager
  from fairseq.tokenizer import tokenize_line
label_desc: Use image node_id 1 for calling a global function with example usage: _worker_prefix(output_prefix, worker_id) and returns: output_prefix, str, worker_id