Method getInstance

public static function getInstance($library = '')
{
    static $instances;
    if (!isset($instances)) {
        $instances = array();
    }
    if (empty($instances[$library])) {
        $instance = new PhocaGalleryLibrary();
        $instances[$library] =& $instance;
    }
    //		Information about all libraries
    //		$this->libraries[$library] = $instances[$library];
    return $instances[$library];
}