How to use the gekko.gk_gui.GK_GUI function in gekko

def GUI(self):
        if not self._gui_open:
            self.gui = GK_GUI(self._path)
            self.gui.display()

if timing == True:
            print('load JSON', time.time() - t)

        if timing == True:
            t = time.time()
        if debug >= 3:
            self.verify_input_options()
            self.gk_logic_tree()
        if timing == True:
            print('debug', time.time() - t)

        if self._gui_open:
            self.gui.update()
        elif GUI is True:
            self._gui_open = True
            self.gui = GK_GUI(self._path)
            self.gui.display()