code: def test_modify_chain_insert(self):
      filter_three = MyFilter()
      self.percolator.insertfilter(filter_three)
      self.filter_two.insert = self.filter_two.uppercase_insert
      self.filter_one.insert = self.filter_one.lowercase_insert
      self.text.insert("insert", "BaR")
      self.assertEqual(self.text.get("1.0", END), "bar\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 9 for calling the PercolatorTest obj's underlying member method code with example usage: obj.test_modify_chain_insert() without return types