public Directory CreateDirectoryFor( string indexName )
        {
            string indexDirectory = null;
            configuration.DirectoryPaths.TryGetValue( indexName, out indexDirectory );
            indexDirectory = indexDirectory ?? System.IO.Path.Combine( configuration.IndexPath, indexName );
            var directoryInfo = System.IO.Directory.CreateDirectory( indexDirectory );
            var qualifiedDirectoryPath = System.IO.Path.GetFullPath( directoryInfo.ToString() );

            var simpleFsDirectory = new SimpleFSDirectory(
                directoryInfo,
                new SimpleFSLockFactory() );

            simpleFsDirectory.EnsureOpen();

            return simpleFsDirectory;
        }