items.add(new TestItem("TestItem1", OpenClosedType.OPEN));
items.add(new TestItem("TestItem2", OpenClosedType.OPEN));
items.add(new TestItem("TestItem3", OpenClosedType.OPEN));
function = new ArithmeticGroupFunction.NAnd(OpenClosedType.OPEN, OpenClosedType.CLOSED);
State state = function.calculate(items);
Assert.assertEquals(OpenClosedType.CLOSED, state);
}