code: def _get_index_page(self):
      try:
          return self._index_page
      except AttributeError:
          index_file = os.path.join(
              os.path.dirname(os.path.abspath(__file__)), "index.html"
          )
          with open(index_file, "r") as file_obj:
              self._index_page = file_obj.read()
          return self._index_page
  
imports: import os
  from .core import MarsRequestHandler
label_desc: Use image node_id 1 for calling the IndexHandler obj's underlying member method code with example usage: obj._get_index_page() and returns: self, self