code: def load_classification_corpus(data_folder) -> CategorizedCorpus:
      train_file = data_folder / "train.txt"
      dev_file = data_folder / "dev.txt"
      test_file = data_folder / "test.txt"
      sentences_train: List[
          Sentence
      ] = DataFetcher.read_text_classification_file(train_file)
      if dev_file.is_file():
          sentences_dev: List[
              Sentence
          ] = DataFetcher.read_text_classification_file(dev_file)
      else:
          sentences_train, sentences_dev = DataFetcher.__sample(
              sentences_train
          )
      sentences_test: List[
          Sentence
      ] = DataFetcher.read_text_classification_file(test_file)
      corpus = CategorizedCorpus(
          sentences_train, sentences_dev, sentences_test
      )
      return corpus
  
imports: import os
  import re
  import shutil
  from enum import Enum
  from os.path import dirname, join
  from typing import Union, List
  import yaml
  from underthesea.corpus import Corpus
  from underthesea.corpus.categorized_corpus import CategorizedCorpus
  from underthesea.corpus.data import Sentence, Label
  from underthesea.file_utils import cached_path, UNDERTHESEA_FOLDER
  from pathlib import Path
  import zipfile
  from underthesea.utils import print_table
label_desc: Use image node_id 8 for calling the DataFetcher obj's underlying member method code with example usage: obj.load_classification_corpus(data_folder) and returns: corpus