public function createMemento()
{
// 创建备忘录
return new Memento($this->_state);
}
public function testMemento() { $originator = new Originator(); $caretaker = new Caretaker(); $originator->state = "On"; $caretaker->memento = $originator->createMemento(); $originator->state = "Off"; $originator->setMemento($caretaker->memento); $this->assertEquals($originator->state, 'On'); }