<?php declare(strict_types=1);

namespace DaveRandom\LibDNS\Records;

use DaveRandom\Enum\Enum;

abstract class ResourceClasses extends Enum
{
    const IN = 1;
    const CS = 2;
    const CH = 3;
    const HS = 4;
}

<?php declare(strict_types=1);

namespace DaveRandom\LibDNS\Records;

use DaveRandom\Enum\Enum;

abstract class ResourceClasses extends Enum
{
    const IN = 1;
    const CH = 3;
    const HS = 4;
}

Remove class CS (cannot find spec, not IANA registered)
Remove class CS (cannot find spec, not IANA registered)
