[BUG] Can't disassociate NATGateway from Subnet

[lissdy]

Library name and version

Azure.ResourceManager.Network 1.9.0

Describe the bug

I need to disassociate NATGateway from Subnet with SDK, while set subnetData.NatGatewayId = null, hit below error

Content:
{"error":{"code":"InvalidRequestFormat","message":"Cannot parse the request.","details":[{"code":"MissingJsonReferenceId","message":"Value for reference id is missing. Path properties.natGateway."}]}}

            // get the SubnetResource
            ResourceIdentifier subnetResourceId = SubnetResource.CreateResourceIdentifier(subscriptionId, resourceGroupName, virtualNetworkName, subnetName);
            SubnetResource subnet = client.GetSubnetResource(subnetResourceId);
            SubnetResource result = await subnet.GetAsync();
            var subnetData = result.Data;
            subnetData.NatGatewayId = null;
            var subnetCollection = client.GetVirtualNetworkResource(VirtualNetworkResource.CreateResourceIdentifier(subscriptionId, resourceGroupName, virtualNetworkName)).GetSubnets();
            // hit bad request exception
            var operation = await subnetCollection.CreateOrUpdateAsync(WaitUntil.Started, subnetName, subnetData, default);

Expected behavior

The SDK supports NAT Gateway disassociation

Actual behavior

Hit exception while set NatGatewayId to null

Reproduction Steps

            SubnetResource subnet = client.GetSubnetResource(subnetResourceId);
            SubnetResource result = await subnet.GetAsync();
            var subnetData = result.Data;
            subnetData.NatGatewayId = null;
            await subnet.UpdateAsync(WaitUntil.Started, subnetData);

Environment

No response

[jsquire]

Thank you for your feedback. Tagging and routing to the team member best able to assist.