class_docstr: Test the config system.
class_docstr_tok: ["Test","the","config","system","."]
code: def test_set_option(self):
      with self.assertLogs(
          logger="streamlit.config", level="WARNING"
      ) as cm:
          config._set_option("not.defined", "no.value", "test")
      # cm.output is a list of messages and there shouldn't be any other messages besides one created by this test
      self.assertIn(
          '"not.defined" is not a valid config option. If you previously had this config option set, it may have been removed.',
          cm.output[0],
      )
  
      config._set_option("client.caching", "test", "test")
      self.assertEqual("test", config.get_option("client.caching"))
  
imports: import copy
  import os
  import textwrap
  import unittest
  from unittest.mock import MagicMock, mock_open, patch
  import pytest
  from parameterized import parameterized
  from streamlit import config, env_util
  from streamlit.config_option import ConfigOption
  from streamlit.errors import StreamlitAPIException
label_desc: Use image node_id 26 for calling the ConfigTest obj's underlying member method code with example usage: obj.test_set_option() without return types