class_docstr: Code stack viewer for debugger GUI.
code: def show_stack_frame(self):
      index = self.listbox.index("active")
      if 0 <= index < len(self.stack):
          self.gui.show_frame(self.stack[index])
  
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 8 for calling the StackViewer obj's underlying member method code with example usage: obj.show_stack_frame() without return types