code: def test_tokenizer_oov_flag_and_num_words():
      x_train = ["This text has only known words this text"]
      x_test = ["This text has some unknown words"]
  
      tokenizer = keras.preprocessing.text.Tokenizer(
          num_words=3, oov_token="<unk>"
      )
      tokenizer.fit_on_texts(x_train)
      x_test_seq = tokenizer.texts_to_sequences(x_test)
      trans_text = " ".join(
          tokenizer.index_word[t] for t in x_test_seq[0]
      )
      assert len(x_test_seq[0]) == 6
      assert trans_text == "this <unk> <unk> <unk> <unk> <unk>"
  
imports: from collections import OrderedDict
  import numpy
  import pytest
  from tensorflow import keras
  from keras_preprocessing import text
label_desc: Use image node_id 14 for calling a global function with example usage: test_tokenizer_oov_flag_and_num_words() without return types