* depending on implementation (hint: Template Method Pattern)
*
* @param $recipient Recipient to resolve (e.g. could be a virtual recipient or direct session id)
* @param $listInstance An instance of a Listable class
* depending on implementation (hint: Template Method Pattern)
*
* @param $recipient Recipient to resolve (e.g. could be a virtual recipient or direct session id)
* @param $listInstance An instance of a Listable class