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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def enable_tk(self, app=None):
 """Enable event loop integration with Tk. Parameters app : toplevel :class:`Tkinter.Tk` widget, optional. Running toplevel widget to use. If not given, we probe Tk for an existing one, and create a new one if none is found. Notes ----- If you have already created a :class:`Tkinter.Tk` object, the only thing done by this method is to register with the :class:`InputHookManager`, since creating that object automatically sets ``PyOS_InputHook``. """

        self._current_gui = GUI_TK
        if app is None:
            try:
                import Tkinter as _TK
            except:
                # Python 3
                import tkinter as _TK  # @UnresolvedImport
            app = _TK.Tk()
            app.withdraw()
            self._apps[GUI_TK] = app

        from pydev_ipython.inputhooktk import create_inputhook_tk
        self.set_inputhook(create_inputhook_tk(app))
        return app