Custom TextClock in widget

I try build my custom TextClock and add in widget.

As always, I inherit from TextClock. When I use my class in a widget, the widget does not work, and when I use it in activity, there are no problems. Why can it be so?

public class CustomTextClock extends TextClock {
    public CustomTextClock(Context context) {
        super(context);
    }

    public CustomTextClock(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomTextClock(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public CustomTextClock(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }
}

Answer

Descendants of this class are not supported in widget 🙁