code: def test_initialize(self):
      v = Var(self.root)
      self.assertFalse(v.side_effect)
      v.set("value")
      self.assertTrue(v.side_effect)
  
imports: import unittest
  from test import support
  import gc
  import tkinter
  from tkinter import Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tcl, TclError
  from test.support import ALWAYS_EQ
  from test.test_tkinter.support import AbstractDefaultRootTest
label_desc: Use image node_id 9 for calling the TestVariable obj's underlying member method code with example usage: obj.test_initialize() without return types