code: def __init__(self, normalize, alphabet, validate_fun):
      self.normalize = normalize
      self.alphabet = alphabet
      self.validate_fun = validate_fun
  
file_path: DeepSpeech/bin/import_cv2.py
imports: import csv
  import os
  import subprocess
  import unicodedata
  from multiprocessing import Pool
  import progressbar
  import sox
  from deepspeech_training.util.downloader import SIMPLE_BAR
  from deepspeech_training.util.importers import get_counter, get_imported_samples, get_importers_parser, get_validate_label, print_import_report
  from ds_ctcdecoder import Alphabet
label_desc: Use image node_id 1 to create a new LabelFilter object  with example: obj = LabelFilter(normalize, alphabet, validate_fun)