code: public function generate()
  	{
  		// Return if there is no file
  		if ($this->singleSRC == '')
  		{
  			return '';
  		}
  
  		$objFile = FilesModel::findByUuid($this->singleSRC);
  
  		if ($objFile === null)
  		{
  			return '';
  		}
  
  		$allowedDownload = StringUtil::trimsplit(',', strtolower(Config::get('allowedDownload')));
  
  		// Return if the file type is not allowed
  		if (!\in_array($objFile->extension, $allowedDownload))
  		{
  			return '';
  		}
  
  		$file = Input::get('file', true);
  
  		// Send the file to the browser (see #4632 and #8375)
  		if ($file && (!isset($_GET['cid']) || Input::get('cid') == $this->id))
  		{
  			if ($file == $objFile->path)
  			{
  				Controller::sendFileToBrowser($file, (bool) $this->inline);
  			}
  
  			if (isset($_GET['cid']))
  			{
  				throw new PageNotFoundException('Invalid file name');
  			}
  		}
  
  		$this->objFile = $objFile;
  		$this->singleSRC = $objFile->path;
  
  		return parent::generate();
  	}
docs: Return if the file does not exist
  
  @return string