code: public function assetFunction($asset, $serverPath = false) {
          /** @var Request|null $request */
          $request = isset($this->container['request']) ? $this->container['request'] : null;
          $path = \ltrim($asset, '/\\');
          $assetPath = Utils::fixPath($this->container->getRootDir() . '/' . $path);
  
  //        if(!\file_exists($assetPath))
  //            throw new FileException("Asset '$asset' with path '$assetPath' not found");
  
          if(!$serverPath)
              if($request instanceof Request)
                  $assetPath = $request->getSchemeAndHttpHost() . '/' . $path;
              else
                  $assetPath = '/' . $path;
  
          return $assetPath;
      }
docs: Return fixed asset's path.
  
  @param string $asset      Path to the asset
  @param bool   $serverPath Server-related path or web-related
  
  @throws FileException File does not exist on server
  
  @return string