Inheritance: extends Adaptee2, implements Target2
    public function sampleMethod2()
    {
        echo '!!!!!!!!';
    }
}
$adapter = new Adapter(new Adaptee());
$adapter->sampleMethod1();
$adapter->sampleMethod2();
//类适配器
interface Target2
{
    public function sampleMethod1();
    public function sampleMethod2();
}
class Adaptee2
{
    // 源角色
    public function sampleMethod1()
    {
    }
}
class Adapter2 extends Adaptee2 implements Target2
{
    // 适配后角色
    public function sampleMethod2()
    {
    }
}
$adapter = new Adapter2();
$adapter->sampleMethod1();
$adapter->sampleMethod2();