class_docstr: Supply user_line and user_exception functions for Bdb.
code: def __init__(self, gui):
      self.gui = gui  # An instance of Debugger or proxy thereof.
      super().__init__()
  
imports: import bdb
  import os
  from tkinter import *
  from tkinter.ttk import Frame, Scrollbar
  from idlelib import macosx
  from idlelib.scrolledlist import ScrolledList
  from idlelib.window import ListedToplevel
label_desc: Use image node_id 1 to create a new Idb object from inherited base classes: bdb with example: obj = Idb(gui)