docstr: Do nothing (return None) to not modify item.
docstr_tok: ["Do","nothing","(","return","None",")","to","not","modify","item","."]
code: def on_nav(self, nav, **kwargs) -> None:
      """Do nothing (return None) to not modify item."""
      return None
  
imports: from __future__ import annotations
  import os
  import unittest
  from typing import TYPE_CHECKING, Optional
  from mkdocs import plugins
  from mkdocs.commands import build
  from mkdocs.config import base
  from mkdocs.config import config_options
  from mkdocs.config.base import ValidationError
  from mkdocs.exceptions import Abort, BuildError, PluginError
  from mkdocs.tests.base import load_config, tempdir
label_desc: Use image node_id 2 for calling the DummyPlugin obj's underlying member method code with example usage: obj.on_nav(nav) and returns: None