public function mergeResources(array $uris, $absolute = true, $all = false)
    {
        $uris = array_unique($uris);

        $lists = [[]];
        foreach ($uris as $uri) {
            $lists[] = $this->findResources($uri, $absolute, $all);
        }

        // TODO: In PHP 5.6+ use array_merge(...$list);
        return call_user_func_array('array_merge', $lists);
    }