code: def switch_to(self, ilabel: int) -> Iterator[None]:
      with self.backtrack():
          self.parser.stack = self._points[ilabel]
          try:
              yield
          except ParseError:
              self._dead_ilabels.add(ilabel)
          finally:
              self.parser.stack = self._start_point
  
imports: from contextlib import contextmanager
  from typing import TYPE_CHECKING, Any, Callable, Dict, Iterator, List, Optional, Set, Tuple, Union, cast
  from blib2to3.pgen2.grammar import Grammar
  from blib2to3.pytree import NL, Context, Leaf, Node, RawNode, convert
  from .None import grammar, token, tokenize
label_desc: Use image node_id 3 for calling the Recorder obj's underlying member method code with example usage: obj.switch_to(ilabel) without return types