public function addSender($channel, $sender)
    {
        $sender = is_string($sender) ? singleton($sender) : $sender;
        $this->senders[$channel] = $sender;

        return $this;
    }
public function addSender($channel, $sender)
    {
        $sender = is_string($sender) ? singleton($sender) : $sender;
        $this->senders[$channel] = $sender;

        return $this;
    }
public function addSender ( $ channel , $ sender ) { $ sender = is_string ( $ sender ) ? singleton ( $ sender ) : $ sender ; $ this -> senders [ $ channel ] = $ sender ; return $ this ; }
Add a notification sender
@param string                    $channel The channel to send through
@param NotificationSender|string $sender  The notification channel
@return \Symbiote\Notifications\Service\NotificationService
Add a notification sender