Tweaking WCF to build highly scalable async REST API

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace AsyncServiceLibrary
{
    public class CompletedAsyncResult<T> : IAsyncResult
    {
        private T CustomData;
        private object wcfState;

        public CompletedAsyncResult(T data, object wcfState)
        {
            this.CustomData = data;
            this.wcfState = wcfState;
        }

        public T Data
        {
            get
            {
                return CustomData;
            }
        }

        #region IAsyncResult Members
        public object AsyncState
        {
            get
            {
                return this.wcfState;
            }
        }

        public WaitHandle AsyncWaitHandle
        {
            get
            {
                throw new Exception("The method or operation is not implemented.");
            }
        }

        public bool CompletedSynchronously
        {
            get
            {
                return true;
            }
        }

        public bool IsCompleted
        {
            get
            {
                return true;
            }
        }
        #endregion
    }
    
}