code: def _init_treelet(self, parent):
      self._treelet_canvas = Canvas(parent, background="white")
      self._treelet_canvas.pack(side="bottom", fill="x")
      self._treelet = None
  
imports: import re
  from tkinter import Button, Canvas, Entry, Frame, IntVar, Label, Scrollbar, Text, Tk, Toplevel
  from nltk.draw.tree import TreeSegmentWidget, tree_to_treesegment
  from nltk.draw.util import CanvasFrame, ColorizedList, ShowText, SymbolWidget, TextWidget
  from nltk.grammar import CFG, Nonterminal, _read_cfg_production, nonterminals
  from nltk.tree import Tree
label_desc: Use image node_id 6 for calling the CFGDemo obj's underlying member method code with example usage: obj._init_treelet(parent) without return types