setDefaultNamespacePrefix example

public function testFilterXPathWithDefaultNamespace()
    {
        $crawler = $this->createTestXmlCrawler()->filterXPath('//default:entry/default:id');
        $this->assertCount(1, $crawler, '->filterXPath() automatically registers a namespace');
        $this->assertSame('tag:youtube.com,2008:video:kgZRZmEc9j4', $crawler->text());
    }

    public function testFilterXPathWithCustomDefaultNamespace()
    {
        $crawler = $this->createTestXmlCrawler();
        $crawler->setDefaultNamespacePrefix('x');
        $crawler = $crawler->filterXPath('//x:entry/x:id');

        $this->assertCount(1, $crawler, '->filterXPath() lets to override the default namespace prefix');
        $this->assertSame('tag:youtube.com,2008:video:kgZRZmEc9j4', $crawler->text());
    }

    public function testFilterXPathWithNamespace()
    {
        $crawler = $this->createTestXmlCrawler()->filterXPath('//yt:accessControl');
        $this->assertCount(2, $crawler, '->filterXPath() automatically registers a namespace');
    }