public function find($paths = null)
    {
        if ($paths === null) $paths = $this->paths;

        // iterator
        $iterator = $this->getIterator();

        // search in target paths
        foreach ((array)$paths as $path) {
            $this->searchInPath($iterator, $path);
        }

        // clear
        $this->clear();

        return $iterator;
    }