Properly Implementing the Chain of Responsibility Pattern

ChainT.cs

using System;

/// <summary>
/// Generic Chain of Responsibility
/// <para>Avoid coupling the sender of a request to its 
/// receiver by giving more than one object a chance to 
/// handle the request. Chain the receiving objects and 
/// pass the request along the chain until an object 
/// handles it.</para>
/// </summary>
public class Chain<TRequest> 
{
    #region Property(s)

    public virtual Chain<TRequest> Successor { get; set; }

    protected virtual Func<TRequest, Boolean> ShouldProcessFunc { get; set; }

    protected virtual Action<TRequest> ProcessAction { get; set; }

    #endregion Property(s)

    #region Constructor(s)

    public Chain(Func<TRequest, Boolean> shouldProcessFunc, Action<TRequest> processAction)
    {
        if (shouldProcessFunc == null)
        {
            throw new ArgumentNullException("shouldProcessFunc");
        }

        if (processAction == null)
        {
            throw new ArgumentNullException("processAction");
        }

        ShouldProcessFunc = shouldProcessFunc;
        ProcessAction = processAction;
    }

    #endregion Constructor(s)

    #region Member(s)

    public void Process(TRequest request)
    {
        if (ShouldProcessFunc.Invoke(request))
        {
            ProcessAction.Invoke(request);
        }
        else
        {
            if(Successor != null)
            {
                Successor.Process(request);
            }
        }
    }

    #endregion Member(s)
}

/// <summary>
/// Generic Chain of Responsibility
/// <para>Avoid coupling the sender of a request to its 
/// receiver by giving more than one object a chance to 
/// handle the request. Chain the receiving objects and 
/// pass the request along the chain until an object 
/// handles it.</para>
/// </summary>
public class Chain<TRequest, TResponse>
{
    #region Property(s)

    public virtual Chain<TRequest, TResponse> Successor { get; set; }

    protected virtual Func<TRequest, Boolean> ShouldProcessFunc { get; set; }

    protected virtual Func<TRequest, TResponse> ProcessFunc { get; set; }

    #endregion Property(s)

    #region Constructor(s)

    public Chain(Func<TRequest, Boolean> shouldProcessFunc, Func<TRequest, TResponse> processFunc)
    {
        if (shouldProcessFunc == null)
        {
            throw new ArgumentNullException("shouldProcessFunc");
        }

        if (processFunc == null)
        {
            throw new ArgumentNullException("processFunc");
        }

        ShouldProcessFunc = shouldProcessFunc;
        ProcessFunc = processFunc;
    }

    #endregion Constructor(s)

    #region Member(s)

    public TResponse Process(TRequest request)
    {
        if (ShouldProcessFunc.Invoke(request))
        {
            return ProcessFunc.Invoke(request);
        }
        else
        {
            if (Successor != null)
            {
                return Successor.Process(request);
            }
            else
            {
                return default(TResponse);
            }
        }
    }

    #endregion Member(s)
}