NServiceBus - Log message headers for all incoming messages via mutator

LogMessageHeadersMutator.cs

using System.Text;
using System.Threading.Tasks;
using NServiceBus.Logging;
using NServiceBus.MessageMutator;

class LogMessageHeadersMutator : IMutateIncomingTransportMessages
{
    static readonly ILog Log = LogManager.GetLogger<LogMessageHeadersMutator>();

    public Task MutateIncoming(MutateIncomingTransportMessageContext context)
    {
        if (!Log.IsDebugEnabled) return Task.CompletedTask;

        var message = new StringBuilder();
        foreach (var h in context.Headers)
        {
            message.AppendLine($"{h.Key} {h.Value}");
        }
        Log.DebugFormat("Headers:\n{0}", message);
        return Task.CompletedTask;
    }
}