internal UsbConfigInfo(MonoUsbDevice usbDevice, MonoUsbConfigDescriptor configDescriptor)
        {
            mUsbDevice = usbDevice;

            mUsbConfigDescriptor = new UsbConfigDescriptor(configDescriptor);

            List<MonoUsbInterface> monoUSBInterfaces = configDescriptor.InterfaceList;
            foreach (MonoUsbInterface usbInterface in monoUSBInterfaces)
            {
                List<MonoUsbAltInterfaceDescriptor> monoUSBAltInterfaces = usbInterface.AltInterfaceList;
                foreach (MonoUsbAltInterfaceDescriptor monoUSBAltInterface in monoUSBAltInterfaces)
                {
                    UsbInterfaceInfo usbInterfaceInfo = new UsbInterfaceInfo(mUsbDevice, monoUSBAltInterface);
                    mInterfaceList.Add(usbInterfaceInfo);
                }
            }
        }
        internal UsbConfigInfo(UsbDevice usbDevice, UsbConfigDescriptor descriptor, ref List<byte[]> rawDescriptors)
        {
            mUsbDevice = usbDevice;
            mUsbConfigDescriptor = descriptor;
            mRawDescriptors = rawDescriptors;

            UsbInterfaceInfo currentInterface = null;
            for (int iRawDescriptor = 0; iRawDescriptor < rawDescriptors.Count; iRawDescriptor++)
            {
                byte[] bytesRawDescriptor = rawDescriptors[iRawDescriptor];

                switch (bytesRawDescriptor[1])
                {
                    case (byte) DescriptorType.Interface:
                        currentInterface = new UsbInterfaceInfo(usbDevice, bytesRawDescriptor);
                        mRawDescriptors.RemoveAt(iRawDescriptor);
                        mInterfaceList.Add(currentInterface);
                        iRawDescriptor--;
                        break;
                    case (byte) DescriptorType.Endpoint:
                        if (currentInterface == null)
                            throw new UsbException(this, "Recieved and endpoint descriptor before receiving an interface descriptor.");

                        currentInterface.mEndpointInfo.Add(new UsbEndpointInfo(bytesRawDescriptor));
                        mRawDescriptors.RemoveAt(iRawDescriptor);
                        iRawDescriptor--;
                        break;
                    default:
                        if (currentInterface != null)
                        {
                            currentInterface.mRawDescriptors.Add(bytesRawDescriptor);
                            mRawDescriptors.RemoveAt(iRawDescriptor);
                            iRawDescriptor--;
                        }
                        break;
                }
            }
        }
        internal static List<UsbConfigInfo> GetDeviceConfigs(UsbDevice usbDevice)
        {
            List<UsbConfigInfo> rtnConfigs = new List<UsbConfigInfo>();

            byte[] cfgBuffer = new byte[UsbConstants.MAX_CONFIG_SIZE];

            int iConfigs = usbDevice.Info.Descriptor.ConfigurationCount;
            for (int iConfig = 0; iConfig < iConfigs; iConfig++)
            {
                int iBytesTransmitted;
                bool bSuccess = usbDevice.GetDescriptor((byte) DescriptorType.Configuration, 0, 0, cfgBuffer, cfgBuffer.Length, out iBytesTransmitted);
                if (bSuccess)
                {
                    if (iBytesTransmitted >= UsbConfigDescriptor.Size && cfgBuffer[1] == (byte) DescriptorType.Configuration)
                    {
                        UsbConfigDescriptor configDescriptor = new UsbConfigDescriptor();
                        Helper.BytesToObject(cfgBuffer, 0, Math.Min(UsbConfigDescriptor.Size, cfgBuffer[0]), configDescriptor);

                        if (configDescriptor.TotalLength == iBytesTransmitted)
                        {
                            List<byte[]> rawDescriptorList = new List<byte[]>();
                            int iRawLengthPosition = configDescriptor.Length;
                            while (iRawLengthPosition < configDescriptor.TotalLength)
                            {
                                byte[] rawDescriptor = new byte[cfgBuffer[iRawLengthPosition]];
                                if (iRawLengthPosition + rawDescriptor.Length > iBytesTransmitted)
                                    throw new UsbException(usbDevice, "Descriptor length is out of range.");

                                Array.Copy(cfgBuffer, iRawLengthPosition, rawDescriptor, 0, rawDescriptor.Length);
                                rawDescriptorList.Add(rawDescriptor);
                                iRawLengthPosition += rawDescriptor.Length;
                            }
                            rtnConfigs.Add(new UsbConfigInfo(usbDevice, configDescriptor, ref rawDescriptorList));
                        }
                        else
                            UsbError.Error(ErrorCode.InvalidConfig,
                                           0,
                                           "GetDeviceConfigs: USB config descriptor length doesn't match the length received.",
                                           usbDevice);
                    }
                    else
                        UsbError.Error(ErrorCode.InvalidConfig, 0, "GetDeviceConfigs: USB config descriptor is invalid.", usbDevice);
                }
                else
                    UsbError.Error(ErrorCode.InvalidConfig, 0, "GetDeviceConfigs", usbDevice);
            }
            return rtnConfigs;
        }