private IEnumerable<FileInfo> InternalEnumerateFiles(String searchPattern, SearchOption searchOption)
{
Debug.Assert(searchPattern != null);
Debug.Assert(searchOption == SearchOption.AllDirectories || searchOption == SearchOption.TopDirectoryOnly);
return (IEnumerable<FileInfo>)FileSystem.Current.EnumerateFileSystemInfos(FullPath, searchPattern, searchOption, SearchTarget.Files);
}