code: def test_expr_grammar(self) -> None:
      grammar = """
          start: sum NEWLINE
          sum: term '+' term | term
          term: NUMBER
          """
      parser_class = make_parser(grammar)
      node = parse_string("42\n", parser_class)
      self.assertEqual(
          node,
          [
              TokenInfo(
                  NUMBER,
                  string="42",
                  start=(1, 0),
                  end=(1, 2),
                  line="42\n",
              ),
              TokenInfo(
                  NEWLINE,
                  string="\n",
                  start=(1, 2),
                  end=(1, 3),
                  line="42\n",
              ),
          ],
      )
  
imports: import ast
  import difflib
  import io
  import textwrap
  import unittest
  from test import test_tools
  from typing import Dict, Any
  from tokenize import TokenInfo, NAME, NEWLINE, NUMBER, OP
label_desc: Use image node_id 6 for calling the TestPegen obj's underlying member method code with example usage: obj.test_expr_grammar() without return types