code: def main():
      global t1, t2, t3
      ht()
      penup()
      goto(0, -225)  # writer turtle
      t1 = Tower(-250)
      t2 = Tower(0)
      t3 = Tower(250)
      # make tower of 6 discs
      for i in range(6, 0, -1):
          t1.push(Disc(i))
      # prepare spartanic user interface ;-)
      write(
          "press spacebar to start game",
          align="center",
          font=("Courier", 16, "bold"),
      )
      onkey(play, "space")
      listen()
      return "EVENTLOOP"
  
file_path: cpython/Lib/turtledemo/minimal_hanoi.py
imports: from turtle import *
label_desc: Use image node_id 3 for calling a global function with example usage: main() and returns: str