Support for opendir().
$uri: A string containing the URI to the directory to open.
$options: Unknown (parameter is not documented in PHP Manual).
TRUE on success.
Overrides StreamWrapperInterface::dir_opendir
http://php.net/manual/streamwrapper.dir-opendir.php
public function dir_opendir($uri, $options) {
$this->uri = $uri;
$this->handle = opendir($this
->getLocalPath());
return (bool) $this->handle;
}