PHP 8.4 ::walk(): Implicitly marking parameter $startAt as nullable is deprecated

[terr17216]

When loading a class I get an error
Deprecated: FreeDSx\\Snmp\\SnmpClient::walk(): Implicitly marking parameter $startAt as nullable is deprecated, the explicit nullable type must be used instead

Solved the problem by changing the method FreeDSx\Snmp\SnmpClient:

old:

public function walk(
        string $startAt = null,
        string $endAt = null
    ): SnmpWalk {
        return new SnmpWalk(
            $this,
            $startAt,
            $endAt
        );
    }

new:

public function walk(
        null|string $startAt,
        null|string $endAt
    ): SnmpWalk {
        return new SnmpWalk(
            $this,
            $startAt,
            $endAt
        );
    }