Can't get Peters Example regarding Jungle Files running

Hi,

I tried to complete this project from Peter: click

I defined a new App

class JungleApp extends Application.AppBase {

    function initialize() {
        AppBase.initialize();
    }

    // onStart() is called on application start up
    function onStart(state) {
    }

    // onStop() is called when your application is exiting
    function onStop(state) {
    }

    //! Return the initial view of your application here
    function getInitialView() {
        return [ new JungleView() ];
    }

}

and did some basic stuff in the JungleView class:

class JungleView extends WatchUi.DataField {

    hidden var mValue;

    function initialize() {
        DataField.initialize();
    }


    // Display the value you computed here. This will be called
    // once a second when the data field is visible.
    function onUpdate(dc) {
    	//System.println(width);
        dc.setColor(Gfx.COLOR_WHITE, Graphics.COLOR_TRANSPARENT);
        //dc.drawText(width / 2, height / 2, Graphics.FONT_NUMBER_THAI_HOT, timeString, Graphics.TEXT_JUSTIFY_CENTER | Graphics.TEXT_JUSTIFY_VCENTER);

        dc.setColor(Gfx.COLOR_BLUE, Graphics.COLOR_TRANSPARENT);
        dc.drawText(120, 140, Graphics.FONT_SMALL, "I'm standard!", Graphics.TEXT_JUSTIFY_CENTER);
    }

}

Then I defined another class which exteds the DataField as well:

using Toybox.WatchUi as Ui;

var width;
var heigth;
	
	
class CommonLogicView extends Ui.DataField {



    // this is called whenever the screen needs to be updated
    function onUpdate(dc) {
        // Common update of the screen: Clear the screen with the backgroundcolor.
        clearScreen(dc);
        
        // We can also do common calculations here, in this case we'll just get the current time
        //determineClockTime();
    }
    
    // clears the screen and stores the width & height in global variables
    function clearScreen(dc) {
        dc.clear();
        width = dc.width;
        height = dc.height;
        System.println("Hallo, I am Common Logic");
    }
}

I have written some device specific files as well, but anyway, I can't see the message "Hallo. I am common Logic" anywhere, so it seems that the code does not run at all. In my understanding the class CommonLogicView extends the Datafield class and I thought as soon as onUpdate is fired, the function in the CommonLogicView runs as well. Am I wrong?

Thanks for helping.