public FileSystemVirtualPathProvider(DirectoryInfo rootDirInfo)
            : base()
        {
            if (rootDirInfo == null)
                throw new ArgumentNullException("rootDirInfo");

            this.RootDirInfo = rootDirInfo;

            if (!RootDirInfo.Exists)
                throw new ApplicationException(
                    String.Format("RootDir '{0}' for virtual path does not exist", RootDirInfo.FullName));

            RootDir = new FileSystemVirtualDirectory(this, null, RootDirInfo);
        }
        public FileSystemVirtualPathProvider(DirectoryInfo rootDirInfo)
            : base()
        {
            if (rootDirInfo == null)
            {
                throw new ArgumentNullException("rootDirInfo");
            }

            this.RootDirInfo = rootDirInfo;

            if (!RootDirInfo.Exists)
            {
                throw new ApplicationException(
                          String.Format("RootDir '{0}' for virtual path does not exist", RootDirInfo.FullName));
            }

            RootDir = new FileSystemVirtualDirectory(this, null, RootDirInfo);
        }