function chatSendServerMessage($message, $recipient = null, $multicall = false)
    {
        $logins = $this->getLogins($recipient, true);
        if ($logins === false) {
            throw new InvalidArgumentException('recipient = ' . print_r($recipient, true));
        }

        if (is_array($message)) {
            return $this->execute(ucfirst(__FUNCTION__) . 'ToLanguage', array($message, $logins), $multicall);
        }
        if (is_string($message)) {
            if ($logins) {
                return $this->execute(ucfirst(__FUNCTION__) . 'ToLogin', array($message, $logins), $multicall);
            }
            return $this->execute(ucfirst(__FUNCTION__), array($message), $multicall);
        }
        // else
        throw new InvalidArgumentException('message = ' . print_r($message, true));
    }