'Starts event loop - calling Tkinter\'s mainloop function.
No argument.
Must be last statement in a turtle graphics program.
Must NOT be used if a script is run from within IDLE in -n mode
(No subprocess) - for interactive use of turtle graphics.
Example (for a TurtleScreen instance named screen):
>>> screen.mainloop()'

def mainloop(self):

    TK.mainloop()
