/// <summary>
        ///     The add followup step.
        /// </summary>
        /// <param name="next">
        ///     The next.
        /// </param>
        public void AddFollowupStep(IItemReceiver <TOut> next)
        {
            if (next == null)
            {
                return;
            }

            if (outputs.Contains(next))
            {
                return;
            }

            outputs.Add(next);
        }
 /// <summary>
 ///     The remove followup step.
 /// </summary>
 /// <param name="next">
 ///     The next.
 /// </param>
 public void RemoveFollowupStep(IItemReceiver <TOut> next)
 {
     outputs.Remove(next);
 }