Exceptions

lib/src/Core/AsyncQueue.dart

@@ -33,6 +33,7 @@ class AsyncQueue<T> extends AsyncReply<T>
                   if (_list[i].ready)
                   {
                       super.trigger(_list[i].result);
+                      super.ready = false;
                       _list.removeAt(i);
                       i--;
                   }

lib/src/Core/AsyncReply.dart

@@ -50,6 +50,11 @@ class AsyncReply<T> implements Future<T>
         return _resultReady;
     }
 
+    set ready(value)
+    {
+        _resultReady = value; 
+    }
+    
     T get result
     {
         return _result;

lib/src/Core/ExceptionCode.dart

@@ -3,6 +3,8 @@ enum ExceptionCode
 {
         HostNotReachable,
         AccessDenied,
+        UserNotFound,
+        ChallengeFailed,
         ResourceNotFound,
         AttachDenied,
         InvalidMethod,