code: def test_token0_has_sent_start_true():
      doc = Doc(Vocab(), words=["hello", "world"])
      assert doc[0].is_sent_start is True
      assert doc[1].is_sent_start is None
      assert not doc.has_annotation("SENT_START")
  
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 15 for calling a global function with example usage: test_token0_has_sent_start_true() without return types