public function __getSerialisablePropertyValue($propertyName) {
        $map = $this->__getSerialisablePropertyMap();
        if (array_key_exists($propertyName, $map)) {
            return $map [$propertyName];
        } elseif (array_key_exists(substr(strtoupper($propertyName), 0, 1) . substr($propertyName, 1), $map)) {
            return $map [substr(strtoupper($propertyName), 0, 1) . substr($propertyName, 1)];
        } else {
            throw new PropertyNotReadableException (get_class($this), $propertyName);
        }
    }