code: def test_is_sent_end(en_tokenizer):
      doc = en_tokenizer("This is a sentence. This is another.")
      assert doc[4].is_sent_end is None
      doc[5].is_sent_start = True
      assert doc[4].is_sent_end is True
      assert len(list(doc.sents)) == 2
  
imports: import numpy
  import pytest
  from spacy.attrs import IS_ALPHA, IS_DIGIT, IS_LOWER, IS_PUNCT, IS_STOP, IS_TITLE
  from spacy.symbols import VERB
  from spacy.tokens import Doc
  from spacy.training import Example
  from spacy.vocab import Vocab
label_desc: Use image node_id 11 for calling a global function with example usage: test_is_sent_end(en_tokenizer) without return types