public async Task <TResponse> Handle(ReceiveContext <TMessage> context, MessageHandlerDelegate <ReceiveContext <TMessage>, TMessage, TResponse> nextHandler)
{
Guard.NotNull(nextHandler, nameof(nextHandler));
Guard.NotNull(context, nameof(context));
var response = await nextHandler(context);
var tasks = this.outbox.Dequeue().Select(e => context.Publish((dynamic)e))
.Cast <Task>()
.ToList();
await Task.WhenAll(tasks);
return(response);
}