code: public function build()
      {
          $assetManager = new AssetManager();
          $filterManager = new FilterManager();
          foreach ($this->filters as $filterName => $filter) {
              $filterManager->set($filterName, $filter);
          }
          $assetsFactory = new AssetFactory($this->configurationHandler->webDir());
          $assetsFactory->setAssetManager($assetManager);
          $assetsFactory->setFilterManager($filterManager);
  
          return $assetsFactory;
      }
docs: Builds the AssetFactory object
  
  @return \Assetic\Factory\AssetFactory