AssetManager\Service\AssetManager::resolvesToAsset PHP Method

    public function resolvesToAsset(RequestInterface $request)
    {
        if (null === $this->asset) {
            $this->asset = $this->resolve($request);
        }
        return (bool) $this->asset;
    }

 public function testClearOutputBufferInSetAssetOnResponse()
 {
     $this->expectOutputString(file_get_contents(__FILE__));
     echo "This string would definately break any image source.\n";
     echo "This one would make it even worse.\n";
     echo "They all should be gone soon...\n";
     $assetFilterManager = new AssetFilterManager();
     $assetCacheManager = $this->getAssetCacheManagerMock();
     $mimeResolver = new MimeResolver();
     $assetManager = new AssetManager($this->getResolver(), array('clear_output_buffer' => true));
     $assetFilterManager->setMimeResolver($mimeResolver);
     $assetManager->setAssetFilterManager($assetFilterManager);
     $assetManager->setAssetCacheManager($assetCacheManager);
     $assetManager->resolvesToAsset($this->getRequest());
     $response = $assetManager->setAssetOnResponse(new Response());
     echo $response->getContent();
 }