$obj = new Car();$obj->name = $this->name;这两句时干什么的？具体详细是什么意思呢

class Car {
   public $name = 'car';
   
   public function __clone() {
       $obj = new Car();
       $obj->name = $this->name;
   }
}
$a = new Car();
$a->name = 'new car';
$b = clone $a;
var_dump($b);