code: def __init__(
      self, filename: Path, stream: Optional[IO[str]] = None
  ) -> None:
      close_stream = None
      if stream is None:
          data = pkgutil.get_data(
              "blib2to3", os.path.basename(filename)
          )
          if data:
              stream = io.StringIO(data.decode("utf-8"))
          else:
              stream = open(filename, encoding="utf-8")
          close_stream = stream.close
      self.filename = filename
      self.stream = stream
      self.generator = tokenize.generate_tokens(stream.readline)
      self.gettoken()  # Initialize lookahead
      self.dfas, self.startsymbol = self.parse()
      if close_stream is not None:
          close_stream()
      self.first = {}  # map from symbol name to set of tokens
      self.addfirstsets()
  
imports: import os
  from typing import IO, Any, Dict, Iterator, List, NoReturn, Optional, Sequence, Tuple, Union
  from blib2to3.pgen2 import grammar, token, tokenize
  from blib2to3.pgen2.tokenize import GoodTokenInfo
  import pkgutil
  import io
label_desc: Use image node_id 1 to create a new ParserGenerator object  with example: obj = ParserGenerator(filename, stream)