/// <summary>
        /// Adds an existing file to the project in response to the "Include In Project" command
        /// </summary>
        /// <param name="parentID"></param>
        /// <param name="Path"></param>
        /// <returns></returns>
        internal int AddFileItem(uint parentID, string Path)
        {
            Microsoft.VisualStudio.FSharp.ProjectSystem.HierarchyNode parent;
            if (parentID == VSConstants.VSITEMID_ROOT)
            {
                parent = FSProjectManager;
            }
            else
            {
                parent = FSProjectManager.NodeFromItemId(parentID);
            }

            var node = FSProjectManager.AddNewFileNodeToHierarchy(parent, Path);

            return(VSConstants.S_OK);
        }