code: def index_suffix(self, checking):
      if checking:
          # when checking links, we need to write out the exact filename
          return "/index.rst"
      return "/index"
  
imports: import abc
  import argparse
  import contextlib
  import difflib
  import enum
  import glob
  import itertools
  import json
  import nbformat
  import os.path
  import re
  import subprocess
  import sys
  import textwrap
label_desc: Use image node_id 1 for calling the Rst obj's underlying member method code with example usage: obj.index_suffix(checking) and returns: str, str