ImportMapRenderer example

namespace Symfony\Component\AssetMapper\Tests\ImportMap;

use PHPUnit\Framework\TestCase;
use Symfony\Component\AssetMapper\ImportMap\ImportMapManager;
use Symfony\Component\AssetMapper\ImportMap\ImportMapRenderer;

class ImportMapRendererTest extends TestCase
{
    public function testBasicRenderNoEntry()
    {
        $renderer = new ImportMapRenderer($this->createImportMapManager());
        $html = $renderer->render();
        $this->assertStringContainsString(<<<EOF <script type="importmap"> {"imports":{}} </script> EOF,
            $html
        );
        $this->assertStringContainsString('<script async src="https://ga.jspm.io/npm:es-module-shims', $html);
    }