code: def lowercase_insert(self, index, chars, tags=None):
      chars = chars.lower()
      self.delegate.insert(index, chars)
  
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 5 for calling the MyFilter obj's underlying member method code with example usage: obj.lowercase_insert(index, chars, tags) without return types