code: def _parse_incr(self, source_file) -> Iterable[conllu.TokenList]:
      fields = ["id", "form", "ner", "relations", "relation_heads"]
      field_parsers = {
          "relations": lambda line, i: json.loads(
              line[i].replace("'", '"')
          ),
          "relation_heads": lambda line, i: json.loads(line[i]),
      }
      metadata_parsers = {"__fallback__": lambda k, v: tuple(k.split())}
  
      lines: List[str] = []
      for index, line in enumerate(source_file):
          if index > 0 and line.startswith("#"):
              source_str = "".join(lines)
              src_token_list = conllu.parse(
                  source_str,
                  fields=fields,
                  field_parsers=field_parsers,
                  metadata_parsers=metadata_parsers,
              )
              lines = []
              yield src_token_list[0]
  
          lines.append(line)
  
      source_str = "".join(lines)
      src_token_list = conllu.parse(
          source_str,
          fields=fields,
          field_parsers=field_parsers,
          metadata_parsers=metadata_parsers,
      )
      yield src_token_list[0]
  
imports: import bisect
  import io
  import json
  import logging
  import os
  import re
  from collections import defaultdict
  from pathlib import Path
  from typing import Any, Dict, Iterable, List, Optional, Set, Tuple, Union
  import conllu
  import gdown
  from conllu.models import Metadata, Token
  import flair
  from flair.data import Sentence
  from flair.datasets.sequence_labeling import ColumnCorpus
  from flair.file_utils import cached_path
  from flair.splitter import SegtokSentenceSplitter, SentenceSplitter
label_desc: Use image node_id 2 for calling the RE_ENGLISH_CONLL04 obj's underlying member method code with example usage: obj._parse_incr(source_file) without return types