code: def search_index(search_term, index_filename):
      byte_flag = False
      data_length = start_byte = 0
      index_file = open(index_filename, "r")
      csv_reader = csv.reader(index_file, delimiter=":")
      for line in csv_reader:
          if not byte_flag and search_term == line[2]:
              start_byte = int(line[0])
              byte_flag = True
          elif byte_flag and int(line[0]) != start_byte:
              data_length = int(line[0]) - start_byte
              break
      index_file.close()
      return start_byte, data_length
  
imports: import ast
  import glob
  import pickle
  import uuid
  from typing import List, Optional
  import os
  import bz2
  import csv
  import numpy
  import pandas
  import pytest
  from matplotlib import pyplot
  from langchain.docstore.document import Document
  from langchain.document_loaders import MWDumpLoader
  from joblib import Parallel, delayed
label_desc: Use image node_id 3 for calling a global function with example usage: search_index(search_term, index_filename) and returns: start_byte,  data_length