public function __construct(array $config = array())
{
$config = $this->normalizeConfig($config);
$this->setDir($config['dir']);
$this->setExt($config['ext']);
$this->setGzip($config['gzip']);
$this->setCache($config['cache']);
$this->setFormatter($config['formatter']);
$this->setSwapMemoryLimit($config['swap_memory_limit']);
}