PHP:如何为集合做一个包装器，每次调用它都会返回集合的下一个元素

class CollectionWrapper implements Iterator {
    private $collection;
    private $position;

    public function __construct($collection) {
        $this->collection = $collection;
        $this->position = 0;
    }

    public function rewind() {
        $this->position = 0;
    }

    public function current() {
        return $this->collection[$this->position];
    }

    public function key() {
        return $this->position;
    }

    public function next() {
        $this->position++;
    }

    public function valid() {
        return isset($this->collection[$this->position]);
    }
}

// 使用示例
$myCollection = [1, 2, 3, 4, 5];
$wrapper = new CollectionWrapper($myCollection);

foreach ($wrapper as $item) {
    echo $item . " ";
}