public Task SubscribeAsync(MessageDeliveryOptions options, CancellationToken cancellationToken = default)
 {
     foreach (var topic in options.Topics)
     {
         _receiver.SubscribeAsync(new MessageExchangeOptions()
         {
             Topic = topic
         });
     }
     return(Task.CompletedTask);
 }
        public async Task SubscribeAsync(MessageDeliveryOptions options, CancellationToken cancellationToken = default)
        {
            if (options.Topics.Count() == 0)
            {
                throw new ArgumentException($"{nameof(MessageDeliveryOptions.Topics)} count is zero.");
            }

            await TryConnection(_transportReceiver, cancellationToken);

            foreach (var topic in options.Topics)
            {
                await _transportReceiver.SubscribeAsync(new MessageExchangeOptions()
                {
                    Topic = topic
                }, cancellationToken);;
            }
        }