Bug 266146 [CSS] JUnit for: Property retrieval must check instanceof and return null
tests/org.eclipse.e4.ui.tests.css.swt/src/org/eclipse/e4/ui/tests/css/swt/CTabFolderTest.java
CTabFolder folderToTest = createTestCTabFolder("CTabFolder { single: true}");
		assertEquals(true, folderToTest.getSingle());
		assertEquals("true", engine.retrieveCSSProperty(folderToTest, "single", null));
		folderToTest.getShell().close();
		folderToTest = createTestCTabFolder("CTabFolder { single: false}");
		assertEquals(false, folderToTest.getSingle());
		assertEquals("false", engine.retrieveCSSProperty(folderToTest, "single", null));
	}
	
	public void testUnselectedCloseVisible() throws Exception {
		CTabFolder folderToTest = createTestCTabFolder("CTabFolder { unselectedCloseVisible: true}");
		assertEquals(true, folderToTest.getUnselectedCloseVisible());
		assertEquals("true", engine.retrieveCSSProperty(folderToTest, "unselectedCloseVisible", null));
		folderToTest.getShell().close();
		folderToTest = createTestCTabFolder("CTabFolder { unselectedCloseVisible: false}");
		assertEquals(false, folderToTest.getUnselectedCloseVisible());
		assertEquals("false", engine.retrieveCSSProperty(folderToTest, "unselectedCloseVisible", null));
	}
	
	public void testUnselectedImageVisible() throws Exception {
		CTabFolder folderToTest = createTestCTabFolder("CTabFolder { unselectedImageVisible: true}");
		assertEquals(true, folderToTest.getUnselectedImageVisible());
		assertEquals("true", engine.retrieveCSSProperty(folderToTest, "unselectedImageVisible", null));
		folderToTest.getShell().close();
		folderToTest = createTestCTabFolder("CTabFolder { unselectedImageVisible: false}");
		assertEquals(false, folderToTest.getUnselectedImageVisible());
		assertEquals("false", engine.retrieveCSSProperty(folderToTest, "unselectedImageVisible", null));
	}
}