public function whatIs($pattern)
    {
        if (! $this->adapter->isAbsolute($pattern)) {
            $pattern = $this->rootPath . $pattern;
        }

        $paths = $this->adapter->glob($pattern);

        if (count($paths) == 0)
            return 'nothing';
        if (count($paths) == 1)
            return ($this->adapter->isFile($paths[0])) ? 'file' : 'dir';
        return 'collection';
    }