try {
            ko1.getKey(-1);
        }
        catch (IndexOutOfBoundsException e) {
            pass = true;
        }
        assertTrue(pass);
        
        // request width index == itemCount
        pass = false;
        try {
            ko1.getKey(3);
        }
        catch (IndexOutOfBoundsException e) {
            pass = true;
        }
        assertTrue(pass);