$firewall = new HtaccessFirewall('path/to/.htaccess');

$host = IP::fromString('123.0.0.1');

$firewall->deny($host);

$host = IP::fromString('123.0.0.1');

$firewall->undeny($host);

$hosts = $firewall->getDenied();

$firewall->deactivate();

// And to reactivate:
$firewall->reactivate();

$hosts = $firewall->set403Message('You are blocked!');

// And to remove:
$hosts = $firewall->remove403Message();

$filesystem = new YourCustomFilesystem();
$firewall = new HtaccessFirewall('path/to/.htaccess', $filesystem);