Bug 277230 [CSS] CSSTestCase should be CSSSWTTestCase
Because it's in the SWT test package and references the SWT engine.
tests/org.eclipse.e4.ui.tests.css.swt/src/org/eclipse/e4/ui/tests/css/swt/ShellActiveTest.java
static final RGB RED = new RGB(255, 0, 0);
	static final RGB BLUE = new RGB(0, 0, 255);
	
	protected Shell createShell(String styleSheet) {
		Display display = Display.getDefault();
		CSSEngine engine = createEngine(styleSheet, display);
		
		Shell shell = new Shell(display, SWT.NONE);
		
		engine.applyStyles(shell, true);
		shell.pack();
		shell.open();
		return shell;
	}
	
	public void testShellActive() throws Exception {
		Shell shell = createShell("Shell:active {background-color: #FF0000;}\n" +
									"Shell {background-color: #0000FF;}");
		assertEquals(RED, shell.getBackground().getRGB());
		Shell newShell = createShell("Shell { background-color: #0000FF; }");
		assertEquals(BLUE, shell.getBackground().getRGB());
		shell.close();
		newShell.close();
	}
}