/// <summary>
		/// Create a new work item
		/// </summary>
        /// <param name="workItemsGroup">The WorkItemsGroup of this workitem</param>
        /// <param name="wigStartInfo">Work item group start information</param>
		/// <param name="callback">A callback to execute</param>
		/// <param name="state">
		/// The context object of the work item. Used for passing arguments to the work item. 
		/// </param>
		/// <returns>Returns a work item</returns>
		public static WorkItem CreateWorkItem(
			IWorkItemsGroup workItemsGroup,
			WIGStartInfo wigStartInfo,
			WorkItemCallback callback, 
			object state)
		{
			ValidateCallback(callback);
            
			WorkItemInfo workItemInfo = new WorkItemInfo();
			workItemInfo.UseCallerCallContext = wigStartInfo.UseCallerCallContext;
			workItemInfo.UseCallerHttpContext = wigStartInfo.UseCallerHttpContext;
			workItemInfo.PostExecuteWorkItemCallback = wigStartInfo.PostExecuteWorkItemCallback;
			workItemInfo.CallToPostExecute = wigStartInfo.CallToPostExecute;
			workItemInfo.DisposeOfStateObjects = wigStartInfo.DisposeOfStateObjects;
            workItemInfo.WorkItemPriority = wigStartInfo.WorkItemPriority;

			WorkItem workItem = new WorkItem(
				workItemsGroup,
				workItemInfo,
				callback, 
				state);
			return workItem;
		}
		/// <summary>
		/// Create a new work item
		/// </summary>
        /// <param name="workItemsGroup">The work items group</param>
		/// <param name="wigStartInfo">Work item group start information</param>
		/// <param name="workItemInfo">Work item information</param>
		/// <param name="callback">A callback to execute</param>
		/// <param name="state">
		/// The context object of the work item. Used for passing arguments to the work item. 
		/// </param>
		/// <returns>Returns a work item</returns>
        public static WorkItem CreateWorkItem(
            IWorkItemsGroup workItemsGroup,
            WIGStartInfo wigStartInfo,
            WorkItemInfo workItemInfo,
            WorkItemCallback callback,
            object state)
        {
            ValidateCallback(callback);
            ValidateCallback(workItemInfo.PostExecuteWorkItemCallback);

            WorkItem workItem = new WorkItem(
                workItemsGroup,
                new WorkItemInfo(workItemInfo),
                callback,
                state);

            return workItem;
        }