public function getLastAction(Campaign $campaign)
    {
        $lastAction = $this->getEdgeAction($campaign, 'last');

        // If there is a last action, make sure it does not equal the first action.
        if($lastAction){
            $firstAction = $this->getFirstAction($campaign);

            if($lastAction->getId() == $firstAction->getId()){
                return null;
            } else {
                return $lastAction;
            }
        }
    }