code: def test_dont_insert(self):
      self.filter_one.insert = self.filter_one.dont_insert
      self.text.insert("insert", "foo bar")
      self.assertEqual(self.text.get("1.0", END), "\n")
      self.filter_one.insert = self.filter_one.dont_insert
      self.text.insert("insert", "foo bar")
      self.assertEqual(self.text.get("1.0", END), "\n")
  
imports: from idlelib.percolator import Percolator, Delegator
  import unittest
  from test.support import requires
  from tkinter import Text, Tk, END
label_desc: Use image node_id 10 for calling the PercolatorTest obj's underlying member method code with example usage: obj.test_dont_insert() without return types