Microsoft bot framework activity logging middleware

LoggingMiddleware.cs

using System.Threading;
using System.Threading.Tasks;

using Microsoft.Bot.Builder;

using Serilog;

namespace CoreBot.Middleware
{
    public class LoggingMiddleware : IMiddleware
    {
        private readonly ILogger _logger;

        public LoggingMiddleware(ILogger logger)
        {
            _logger = logger;
        }


        public async Task OnTurnAsync(ITurnContext turnContext, NextDelegate next,
            CancellationToken cancellationToken = new CancellationToken())
        {
            _logger.ForContext("activity", turnContext.Activity, true)
                   .Verbose($"{turnContext.Activity.Type} received");

            turnContext.OnSendActivities(async (context, activities, nextSend) =>
            {
                _logger.ForContext("activity", context.Activity, true)
                       .Verbose($"{context.Activity.Type} received");
                return await nextSend();
            });
            turnContext.OnUpdateActivity(async (context, activity, nextUpdate) =>
            {
                _logger.ForContext("activity", context.Activity, true)
                       .Verbose($"{context.Activity.Type} received");
                return await nextUpdate();
            });
            turnContext.OnDeleteActivity(async (context, reference, nextDelete) =>
            {
                _logger.ForContext("activity", context.Activity, true)
                       .Verbose($"{context.Activity.Type} received");
                await nextDelete();
            });

            await next(cancellationToken).ConfigureAwait(false);
        }
    }
}