public IAsyncResult BeginProcessRequest(HttpContext context, AsyncCallback cb, object extraData)
        {
            var login = CreateLogin(context.Request);

            using (var db = new DB())
                Authentication.VerifyUserInRole(context, db, login, Roles.Administrator, @readonly: true);

            var slot = new ObserverSlot(context, cb, extraData);

            lock (slots)
                slots.Add(slot);
            return(slot);
        }
		public IAsyncResult BeginProcessRequest (HttpContext context, AsyncCallback cb, object extraData)
		{
			var login = Authentication.CreateLogin (context.Request);
			using (var db = new DB ())
				Authentication.VerifyUserInRole (context, db, login, Roles.Administrator, @readonly: true);

			var slot = new ObserverSlot (context, cb, extraData);
			lock (slots)
				slots.Add (slot);
			return slot;
		}