private void paintImpl( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
			g.fillRect( x, y, width, 1 );
		}
Window top border used on Windows 10.
No longer needed since Windows 11.
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatNativeWindowBorder.java