Bug 289090 [CommonNavigator] labels are missing
tests/org.eclipse.ui.tests.navigator/src/org/eclipse/ui/tests/navigator/LabelProviderTest.java
public LabelProviderTest() {
		_navigatorInstanceId = "org.eclipse.ui.tests.navigator.OverrideTestView";
	}
	
	
	public void XXXtestBlankLabelProvider() throws Exception {
		TestLabelProvider._blankStatic = true;
		_contentService.bindExtensions(new String[] { TEST_CONTENT_OVERRIDDEN1,
				TEST_CONTENT_OVERRIDE1 }, false);
		_contentService.getActivationService()
				.activateExtensions(
						new String[] { TEST_CONTENT_OVERRIDE1,
								TEST_CONTENT_OVERRIDDEN1 }, true);
		refreshViewer();
		TreeItem[] rootItems = _viewer.getTree().getItems();
		if (!rootItems[0].getText().equals(""))
			fail("Wrong text: " + rootItems[0].getText());
	}
	private void checkItemsAll(TreeItem[] rootItems, TestLabelProvider tlp) {
		if (!rootItems[0].getText().startsWith(tlp.getColorName()))
			fail("Wrong text: " + rootItems[0].getText());
		checkItems(rootItems, tlp);
	}
	
	private void checkItems(TreeItem[] rootItems, TestLabelProvider tlp) {
		assertEquals(tlp.backgroundColor, rootItems[0]
				.getBackground(0));