public IEventStream Load(Guid aggregateId)
        {
            IEventStream eventStream = null;

            if (!streams.TryGetValue(aggregateId, out eventStream))
            {
                eventStream          = new InMemoryEventStream();
                streams[aggregateId] = eventStream;
            }
            return(eventStream);
        }
        public IEventStream Load(Guid aggregateId)
        {
            IEventStream eventStream = null;

            if (!streams.TryGetValue(aggregateId, out eventStream))
            {
                eventStream = new InMemoryEventStream();
                streams[aggregateId] = eventStream;
            }
            return eventStream;
        }