code: def check_intersection(self, first_alt: Alt, second_alt: Alt) -> None:
      if str(second_alt).startswith(str(first_alt)):
          raise ValidationError(
              f"In {self.rulename} there is an alternative that will "
              f"never be visited:\n{second_alt}"
          )
  
file_path: cpython/Tools/peg_generator/pegen/validator.py
imports: from typing import Optional
  from pegen import grammar
  from pegen.grammar import Alt, GrammarVisitor, Rhs, Rule
label_desc: Use image node_id 2 for calling the SubRuleValidator obj's underlying member method code with example usage: obj.check_intersection(first_alt, second_alt) without return types