func adjustBridgeOptions(options map[string]string, usedNetworks *interface{}) (bool, error) {
    checkBridgeConflict := true
    for key, value := range options {
        switch key {
        case types.VLANOption:
            // Validate VLAN
            if _, err := internalutil.ParseVlan(value); err != nil {
                return false, err
            }
            // When VLAN is set, allow multiple bridge configs on the same bridge.
            *usedNetworks = nil
            checkBridgeConflict = false
        case types.ModeOption:
            switch value {
            case types.BridgeModeManaged:
                // No changes needed here.
            case types.BridgeModeUnmanaged:
                // For unmanaged mode, also unset usedNetworks and relax conflict check.
                *usedNetworks = nil
                checkBridgeConflict = false
            default:
                return false, fmt.Errorf("unknown bridge mode %q", value)
            }
        }
    }
    return checkBridgeConflict, nil
}

case types.BridgeNetworkDriver:
    internalutil.MapDockerBridgeDriverOptions(newNetwork)
    checkBridgeConflict := true

    // Validate options and adjust bridge configuration flags.
    // For reference, make sure to process VLAN and Mode options first.
    if got, err := adjustBridgeOptions(newNetwork.Options, &usedNetworks); err != nil {
        return nil, err
    } else {
        checkBridgeConflict = got
    }

    // Process the rest of the options which don't need extra handling.
    for key, value := range newNetwork.Options {
        switch key {
        case types.MTUOption:
            if _, err := internalutil.ParseMTU(value); err != nil {
                return nil, err
            }
        case types.IsolateOption:
            if val, err := internalutil.ParseIsolate(value); err != nil {
                return nil, err
            } else {
                newNetwork.Options[types.IsolateOption] = val
            }
        case types.MetricOption:
            if _, err := strconv.ParseUint(value, 10, 32); err != nil {
                return nil, err
            }
        // ... other options ...
        }
    }

    if err := internalutil.CreateBridge(n, newNetwork, usedNetworks, n.defaultsubnetPools, checkBridgeConflict); err != nil {
        return nil, err
    }