code: public static function addStaticUrlTo($script, ContaoContext $context = null)
  	{
  		// Absolute URLs
  		if (preg_match('@^https?://@', $script))
  		{
  			return $script;
  		}
  
  		if ($context === null)
  		{
  			$context = System::getContainer()->get('contao.assets.assets_context');
  		}
  
  		if ($strStaticUrl = $context->getStaticUrl())
  		{
  			return $strStaticUrl . $script;
  		}
  
  		return $script;
  	}
docs: Add a static URL to a script
  
  @param string             $script  The script path
  @param ContaoContext|null $context
  
  @return string The script path with the static URL