src/Resource.php
public static function getMessage($msgId, $params = array())
    {
        $message = constant($msgId);
        if (isset($message)) {
            $message = I18n::t($message, $msgId, 'system');
            $result = vsprintf($message, $params);
        }
        return $result;
    }
public static function getMessage($msgId, $params = array())
    {
        $message = constant($msgId);
        if (isset($message)) {
            $message = I18n::t($message, $msgId, 'system');
            $result = vsprintf($message, $params);
        }
        return $result;
    }
Get message from CONSTANT, translate and format it
@param string $msgId ID if constant
@param array $params parameter for format (use vsprintf)
@return string