/// <summary>
        /// The child control "ironTextBox" calls this, whenever a TAB key is pressed.
        /// We just relay this information via the standard event mechanism to listeners.
        /// </summary>
        private string CompletionCallback(string uncompleted)
        {
            var args = new CompletionRequestedEventArgs(uncompleted);
            OnCompletionRequested(args);

            // FIXME: have to still find relevant portion for completion...
            if (args.Completed != null)
            {
                return args.Completed;
            }
            else
            {
                return uncompleted;
            }
        }
 protected virtual void OnCompletionRequested(CompletionRequestedEventArgs args)
 {
     if (CompletionRequested != null)
     {
         CompletionRequested(this, args);
     }
 }