Do not just call this Controller directly! It is supposed to be used within ESI requests that are protected by the fragment uri signer of Symfony. If you call it directly, make sure you check for all permissions needed because insert tags can contain arbitrary data!
Inheritance: extends Symfony\Bundle\FrameworkBundle\Controller\Controller
 /**
  * Tests the renderNonCacheableInsertTag() action.
  */
 public function testRenderNonCacheableInsertTag()
 {
     $insertTagAdapter = $this->getMockBuilder('Contao\\CoreBundle\\Framework\\Adapter')->setMethods(['replace'])->disableOriginalConstructor()->getMock();
     $insertTagAdapter->expects($this->any())->method('replace')->willReturn('3858f62230ac3c915f300c664312c63f');
     $controller = new InsertTagsController($this->mockFramework($insertTagAdapter));
     $response = $controller->renderAction('{{request_token}}');
     $this->assertInstanceOf('Symfony\\Component\\HttpFoundation\\Response', $response);
     $this->assertTrue($response->headers->hasCacheControlDirective('private'));
     $this->assertSame('3858f62230ac3c915f300c664312c63f', $response->getContent());
 }