code: def test_train_from_iterator(self):
      text = ["A first sentence", "Another sentence", "And a last one"]
      tokenizer = BertWordPieceTokenizer()
      tokenizer.train_from_iterator(text, show_progress=False)
  
      output = tokenizer.encode("A sentence")
      assert output.tokens == ["a", "sentence"]
  
imports: import pytest
  from tokenizers import BertWordPieceTokenizer
  from ..utils import bert_files, data_dir, multiprocessing_with_parallelism
label_desc: Use image node_id 3 for calling the TestBertWordPieceTokenizer obj's underlying member method code with example usage: obj.test_train_from_iterator() without return types