public FileStream GetFeed(IEnumerable<object> feeds, AmazonEnvelopeMessageType amazonEnvelopeMessageType,
            AmazonEnvelopeMessageOperationType? amazonEnvelopeMessageOperationType)
        {
            if (feeds != null && feeds.Any())
            {
                var messages = new AmazonEnvelopeMessageCollection();
                var msgCounter = 1;
                foreach (var feed in feeds)
                {
                    var message = new AmazonEnvelopeMessage
                    {
                        MessageID = msgCounter.ToString(),
                        Item = feed
                    };
                    if (amazonEnvelopeMessageOperationType != null)
                        message.OperationType = amazonEnvelopeMessageOperationType.Value;
                    messages.Add(message);
                    msgCounter++;
                }
                var amazonEnvelope = new AmazonEnvelope
                {
                    Header = new Header
                    {
                        DocumentVersion = "1.0",
                        MerchantIdentifier = _amazonSellerSettings.SellerId
                    },
                    MessageType = amazonEnvelopeMessageType,
                    Message = messages
                };

                return AmazonAppHelper.GetStream(amazonEnvelope, amazonEnvelopeMessageType);
            }
            return null;
        }
        public FileStream GetSingleFeed(object feed, AmazonEnvelopeMessageType amazonEnvelopeMessageType,
       AmazonEnvelopeMessageOperationType? amazonEnvelopeMessageOperationType)
        {
            if (feed != null)
            {
                var message = new AmazonEnvelopeMessage
                    {
                        MessageID = "1",
                        Item = feed
                    };
                if (amazonEnvelopeMessageOperationType != null)
                    message.OperationType = amazonEnvelopeMessageOperationType.Value;
                var amazonEnvelope = new AmazonEnvelope
                {
                    Header = new Header
                    {
                        DocumentVersion = "1.0",
                        MerchantIdentifier = _amazonSellerSettings.SellerId
                    },
                    MessageType = amazonEnvelopeMessageType,
                    Message = new AmazonEnvelopeMessageCollection(){message}
                };

                return AmazonAppHelper.GetStream(amazonEnvelope, amazonEnvelopeMessageType);
            }
            return null;
        }