code: def test_text_batch_loader():
      path = "loader_test_data_dir"
      test_loader = TextBatchLoader(path)
      df = test_loader.extract()
      contents = sorted(df["text"].tolist())
  
      assert df.size == 8
      assert contents[0] == "1_subdir_1_file.txt content"
  
file_path: FEDOT/test/unit/data/test_file_loader.py
imports: import os
  import pathlib
  import shutil
  from os.path import abspath, basename, join
  import pytest
  from fedot.core.data.load_data import TextBatchLoader
label_desc: Use image node_id 3 for calling a global function with example usage: test_text_batch_loader() without return types