Record example

public function __construct(array &$dnsMap)
    {
        $this->dnsMap = &$dnsMap;
    }

    public function resolve(string $name, int $typeRestriction = null): Promise
    {
        if (!isset($this->dnsMap[$name]) || !\in_array($typeRestriction, [Record::A, null], true)) {
            return Dns\resolver()->resolve($name, $typeRestriction);
        }

        return new Success([new Record($this->dnsMap[$name], Record::A, null)]);
    }

    public function query(string $name, int $type): Promise
    {
        if (!isset($this->dnsMap[$name]) || Record::A !== $type) {
            return Dns\resolver()->query($name, $type);
        }

        return new Success([new Record($this->dnsMap[$name], Record::A, null)]);
    }
}