code: def pysbd_sentence_boundaries(doc):
      seg = pysbd.Segmenter(language="en", clean=False, char_span=True)
      sents_char_spans = seg.segment(doc.text)
      char_spans = [
          doc.char_span(sent_span.start, sent_span.end)
          for sent_span in sents_char_spans
      ]
      start_token_ids = [
          span[0].idx for span in char_spans if span is not None
      ]
      for token in doc:
          token.is_sent_start = (
              True if token.idx in start_token_ids else False
          )
      return doc
  
label_desc: Use image node_id 1 for calling a global function with example usage: pysbd_sentence_boundaries(doc) and returns: doc