internal static extern int BtGattClientForeachServices(BluetoothGattClientHandle clientHandle, BtGattForeachCallback callback, IntPtr userData);
internal static extern int BtGattClientGetRemoteAddress(BluetoothGattClientHandle clientHandle, out string remoteAddress);
internal static extern int BtGattClientGetService(BluetoothGattClientHandle clientHandle, string uuid, out BluetoothGattAttributeHandle serviceHandle);
internal static extern int BtGattClientCreate(string remoteAddress, out BluetoothGattClientHandle clientHandle);