public static void paintComponentBackground( Graphics2D g, int x, int y, int width, int height,
		float focusWidth, float arc )
	{
		paintOutlinedComponent( g, x, y, width, height, focusWidth, 0, 0, 0, arc, null, null, g.getPaint() );
	}
Fills the background of a component with a rounded rectangle.
<p>
The bounds of the painted rounded rectangle are
{@code x + focusWidth, y + focusWidth, width - (focusWidth * 2), height - (focusWidth * 2)}.
The given arc diameter refers to the painted rectangle (and not to {@code x,y,width,height}).

@see #paintOutlinedComponent
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java