function testHigherLower() { $topic = new SListDecorator($this->topics['list_1'], 'forum'); $this->assertEqual($this->topics['list_2'], $topic->lowerItem()); $this->assertNull($topic->higherItem()); $topic = new SListDecorator($this->topics['list_4'], 'forum'); $this->assertEqual($this->topics['list_3'], $topic->higherItem()); $this->assertNull($topic->lowerItem()); }