code: public function resolveApp()
      {
          // Determine the correct vhost first
          $this->determineVirtualHost();
  
          // Resolve the application to start
          $path = $this->vhost->getPath($this->request->url);
  
          $resolved = $this->resolver->resolve("app", $path);
  
          if ($resolved !== null)
          {
              if ($resolved['ext'])
              {
                  $mime = new FileType($resolved['ext'], "");
                  if (!empty($mime))
                  {
                      $str = $mime->getMimeType() . ";q=1.5," . (string)$this->request->accept;
                      $this->request->setAccept(new Accept($str));
                  }
                  $this->suffix = $resolved['ext'];
              }
              $this->route = $resolved['route'];
              $this->app = $resolved['path'];
              $this->arguments = new Dictionary($resolved['remainder']);
          }
          else
          {
              $this->route = null;
              $this->app = null;
              $this->arguments = new Dictionary();
          }
      }
docs: Resolve the app to run based on the incoming URL