@Override
	protected void installDefaults() {
		if( group.getContentPane() instanceof JComponent ) {
			// remove default SwingX content border, which may be still set when switching LaF
			JComponent content = (JComponent) group.getContentPane();
			Border contentBorder = content.getBorder();
			if( contentBorder instanceof CompoundBorder &&
				((CompoundBorder)contentBorder).getOutsideBorder() instanceof BasicTaskPaneUI.ContentPaneBorder &&
				((CompoundBorder)contentBorder).getInsideBorder() instanceof EmptyBorder )
			{
				content.setBorder( null );
			}

			// set non-UIResource color to background to avoid that it is lost when switching LaF
			background = UIManager.getColor( "TaskPane.background" );
			Color bg = content.getBackground();
			if( bg == null || bg instanceof UIResource ) {
				content.setBackground( new Color( background.getRGB(), true ) );
			}
		}

		roundHeight = FlatUIUtils.getUIInt( "TaskPane.roundHeight", UIManager.getInt( "Component.arc" ) );

		super.installDefaults();
	}
Provides the Flat LaF UI delegate for {@link org.jdesktop.swingx.JXTaskPane}.

@author Karl Tauber
flatlaf-swingx/src/main/java/com/formdev/flatlaf/swingx/ui/FlatTaskPaneUI.java