protected function setAdapter($password = null, $prefix)
{
$ext = strtolower($this->ext);
if ($ext == 'tar' || stripos($ext, 'bz') !== false || stripos($ext, 'gz') !== false) {
$class = $prefix . 'Tar';
} else {
$class = $prefix . ucfirst($ext);
}
$this->adapter = null !== $password ? new $class($this, $password) : new $class($this);
}