public static void AddIfCancelManagerPresent(HttpRequestMessage request, IHttpCancel action)
 {
     var manager = request.GetPropertyOrDefault<CancelManager>();
     if (manager != null)
     {
         manager.Add(action);
     }
 }
 public void Add(IHttpCancel action)
 {
     if (list == null)
     {
         list = new List <IHttpCancel>();
     }
     list.Add(action);
 }
 public void Add(IHttpCancel action)
 {
     if (list == null)
     {
         list = new List<IHttpCancel>();
     }
     list.Add(action);
 }
        public static void AddIfCancelManagerPresent(HttpRequestMessage request, IHttpCancel action)
        {
            var manager = request.GetPropertyOrDefault <CancelManager>();

            if (manager != null)
            {
                manager.Add(action);
            }
        }