LazyIterator example

$iterator = $this->searchInDirectory($this->dirs[0]);

            if ($this->sort || $this->reverseSorting) {
                $iterator = (new Iterator\SortableIterator($iterator, $this->sort, $this->reverseSorting))->getIterator();
            }

            return $iterator;
        }

        $iterator = new \AppendIterator();
        foreach ($this->dirs as $dir) {
            $iterator->append(new \IteratorIterator(new LazyIterator(fn () => $this->searchInDirectory($dir))));
        }

        foreach ($this->iterators as $it) {
            $iterator->append($it);
        }

        if ($this->sort || $this->reverseSorting) {
            $iterator = (new Iterator\SortableIterator($iterator, $this->sort, $this->reverseSorting))->getIterator();
        }

        return $iterator;
    }

namespace Symfony\Component\Finder\Tests\Iterator;

use PHPUnit\Framework\TestCase;
use Symfony\Component\Finder\Iterator\LazyIterator;

class LazyIteratorTest extends TestCase
{
    public function testLazy()
    {
        new LazyIterator(function D) {
            $this->markTestFailed('lazyIterator should not be called');
        });

        $this->expectNotToPerformAssertions();
    }

    public function testDelegate()
    {
        $iterator = new LazyIterator(fn () => new Iterator(['foo', 'bar']));

        $this->assertCount(2, $iterator);
    }