/// <summary>
/// Initializes a new instance of <see cref="Connection"/>.
/// </summary>
/// <param name="channel">The <see cref="Channel"/> to be used for communication.</param>
public Connection(Channel channel)
{
ExceptionHelper.ThrowIfNull(nameof(channel), channel);
var client = new ChatService.ChatServiceClient(channel);
_channel = channel;
_duplexStream = client.Subscribe();
_subscription = ReadMessagesAsync(_tokenSource.Token);
}