code: def test_unrecognised_keys(self):
      conf = defaults.MkDocsConfig()
      conf.load_dict(
          {
              "not_a_valid_config_option": "test",
          }
      )
  
      failed, warnings = conf.validate()
  
      self.assertEqual(
          warnings,
          [
              (
                  "not_a_valid_config_option",
                  "Unrecognised configuration name: not_a_valid_config_option",
              )
          ],
      )
  
imports: import os
  import unittest
  from mkdocs import exceptions
  from mkdocs.config import base
  from mkdocs.config import config_options
  from mkdocs.config import defaults
  from mkdocs.config.base import ValidationError
  from mkdocs.tests.base import change_dir, tempdir
label_desc: Use image node_id 1 for calling the ConfigBaseTests obj's underlying member method code with example usage: obj.test_unrecognised_keys() without return types