code: def parse_enum_type_extension(lexer: Lexer) -> EnumTypeExtensionNode:
      
      start = lexer.token
      expect_keyword(lexer, "extend")
      expect_keyword(lexer, "enum")
      name = parse_name(lexer)
      directives = parse_directives(lexer, True)
      values = parse_enum_values_definition(lexer)
      if not (directives or values):
          raise unexpected(lexer)
      return EnumTypeExtensionNode(
          name=name, directives=directives, values=values, loc=loc(lexer, start)
      )
docs: EnumTypeExtension