public function getIfExists($alias)
    {
        $repo = $this->getItemsName();
        $loc = &$this->$repo;
        foreach (explode('.', $alias) as $step) {
            if (array_key_exists($step, $loc)) {
                $loc = &$loc[$step];
            } else {
                return new NoItemFoundMessage($alias);
            }
        }
        return $loc;
    }