public void UnregisterTask(IRunningAction action)
        {
            if(action == null) 
                throw new ArgumentNullException("action");

            if(_runningActions.Contains(action))
            {
                _runningActions.Remove(action);
                OnRunningActionUnregistered(action);
                NotifyOfPropertyChange("HasRunningActions");
            }
        }
        public void UnregisterTask(IRunningAction action)
        {
            if (action == null)
            {
                throw new ArgumentNullException("action");
            }

            if (runningActions.Contains(action))
            {
                runningActions.Remove(action);
                OnRunningActionUnregistered(action);
                NotifyOfPropertyChange("HasRunningActions");
            }
        }
 protected virtual void OnRunningActionUnregistered(IRunningAction action) { }
 protected virtual void OnRunningActionUnregistered(IRunningAction action)
 {
 }