public function sendTemplate($templateName, Message $message, array $templateContent = array(), $async = false, $ipPool = NULL, $sendAt = NULL){
        if(!sizeof($templateContent)){
            $templateContent = array('');   // Mandrill will not accept an empty array for template_content, but it does not require any actual content.
        }
        return $this->request('send-template', array(
            'template_name' => $templateName,
            'template_content'=> $templateContent,
            'message' => $message->toArray(),
            'async' => $async,
            'ip_pool' => $ipPool,
            'send_at' => $sendAt
        ));
    }