code: def test_mainloop(self):
      log = []
  
      def callback():
          log.append(1)
          self.root.after(100, self.root.quit)
  
      self.root.after(100, callback)
      self.root.mainloop(1)
      self.assertEqual(log, [])
      self.root.mainloop(0)
      self.assertEqual(log, [1])
      self.assertTrue(self.root.winfo_exists())
  
imports: import functools
  import unittest
  import tkinter
  from tkinter import TclError
  import enum
  from test import support
  from test.test_tkinter.support import AbstractTkTest, AbstractDefaultRootTest, requires_tk
label_desc: Use image node_id 18 for calling the MiscTest obj's underlying member method code with example usage: obj.test_mainloop() without return types