code: def test_bag_of_words(_nltk, text_data):
      bag = to_list(
          bag_of_words_to_docs(
              preprocess_texts(text_data["test_list_main"])
          )
      )
  
      assert len(text_data["test_list_main"]) == len(
          bag
      ), "Number of documents in input does not match number of documents in output"
      assert isinstance(
          bag, list
      ), "Output is not of the expected return type of list"
      assert isinstance(
          bag[0], str
      ), "Output does not contain expected type of string inside of return value"
  
file_path: data-describe/tests/test_text_preprocessing.py
imports: import pytest
  import pandas
  from data_describe.text.text_preprocessing import tokenize, to_lower, remove_digits, remove_punct, remove_single_char_and_spaces, remove_stopwords, preprocess_texts, to_list, bag_of_words_to_docs, create_doc_term_matrix, create_tfidf_matrix, ngram_freq
label_desc: Use image node_id 9 for calling a global function with example usage: test_bag_of_words(_nltk, text_data) without return types