private boolean contains( Rectangle rect, Point pt ) {
			return (rect != null && rect.contains( pt ) );
		}
Because there may be sent many WM_DWMCOLORIZATIONCOLORCHANGED messages,
slightly delay event firing and fire it only once (on the AWT thread).
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatWindowsNativeWindowBorder.java