code: def test_char_span(doc, i_sent, i, j, text):
      sents = list(doc.sents)
      span = sents[i_sent].char_span(i, j)
      if not text:
          assert not span
      else:
          assert span.text == text
  
imports: import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from thinc.api import get_current_ops
  from spacy.attrs import LENGTH, ORTH
  from spacy.lang.en import English
  from spacy.tokens import Doc, Span, Token
  from spacy.util import filter_spans
  from spacy.vocab import Vocab
  from ..util import add_vecs_to_vocab
  from .test_underscore import clean_underscore
label_desc: Use image node_id 11 for calling a global function with example usage: test_char_span(doc, i_sent, i, j, text) without return types