Method gc

/**
 * Garbage collect expired cache data
 *
 * @return  boolean
 *
 * @since   1.7.0
 */
public function gc()
{
    $result = true;
    // Files older than lifeTime get deleted from cache
    $files = $this->_filesInFolder($this->_root, '', true, true, array('.svn', 'CVS', '.DS_Store', '__MACOSX', 'index.html'));
    foreach ($files as $file) {
        $time = @filemtime($file);
        if ($time + $this->_lifetime < $this->_now || empty($time)) {
            File::invalidateFileCache($file);
            $result |= @unlink($file);
        }
    }
    return (bool) $result;
}