appendix gturtlescreen methods method description screen onclick(funbtn= add=nonebind fun to mouse-click event on canvas argumentsfun function with two argumentsthe coordinates of the clicked point on the canvas num the number of the mouse-buttondefaults to example (for turtlescreen instance named screen and turtle instance named turtle)screen onclick(turtle goto##subsequently clicking into the turtlescreen will ##make the turtle move to the clicked point screen onclick(none##event-binding will be removed screen onkey(funkeybind fun to key-release event of key argumentsfun function with no arguments key stringkey ( " "or key-symbol ( "space"in order to be able to register key-eventsturtlescreen must have focus (see method listen example (for turtlescreen instance named screen and turtle instance named turtle)def ()turtle fd( turtle lt( screen onkey( "up"screen listen(##subsequently the turtle can be moved by ##repeatedly pressing the up-arrow key##consequently drawing hexagon this copy belongs to 'acha